MDPI publications

Permanent URI for this collectionhttps://hdl.handle.net/10657/15459

This collection gathers materials published by University of Houston authors in MDPI journals

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Now showing 1 - 20 of 94

Fixed-Point Results of Generalized (ϕ,Ψ)-Contractive Mappings in Partially Ordered Controlled Metric Spaces with an Application to a System of Integral Equations
(2024-06-20) Akram, Mohammad; Alshaikey, Salha; Ishtiaq, Umar; Farhan, Muhammad; Argyros, Ioannis K.; Regmi, Samundra
In this manuscript, we prove numerous results concerning fixed points, common fixed points, coincidence points, coupled coincidence points, and coupled common fixed points for (ϕ,Ψ)-contractive mappings in the framework of partially ordered controlled metric spaces. Our findings introduce a novel perspective on this mathematical context, and we illustrate the uniqueness of our findings through various explanatory examples. Also, we apply the main result to find the existence and uniqueness of the solution of the system of integral equations as an application.
Data and Energy Impacts of Intelligent Transportation—A Review
(2024-06-17) Rajashekara, Kaushik; Koppera, Sharon
The deployment of intelligent transportation is still in its early stages and there are many challenges that need to be addressed before it can be widely adopted. Autonomous vehicles are a class of intelligent transportation that is rapidly developing, and they are being deployed in selected cities. A combination of advanced sensors, machine learning algorithms, and artificial intelligence are being used in these vehicles to perceive their environment, navigate, and make the right decisions. These vehicles leverage extensive data sourced from various sensors and computers integrated into the vehicle. Hence, massive computational power is required to process the information from various built-in sensors in milliseconds to make the right decision. The power required by the sensors and the use of additional computational power increases the energy consumption, and, hence, could reduce the range of the autonomous electric vehicle relative to a standard electric car and lead to additional emissions. A number of review papers have highlighted the environmental benefits of autonomous vehicles, focusing on aspects like optimized driving, improved route selection, fewer stops, and platooning. However, these reviews often overlook the significant energy demands of the hardware systems—such as sensors, computers, and cameras—necessary for full autonomy, which can decrease the driving range of electric autonomous vehicles. Additionally, previous studies have not thoroughly examined the data processing requirements in these vehicles. This paper provides a more detailed review of the volume of data and energy usage by various sensors and computers integral to autonomous features in electric vehicles. It also discusses the effects of these factors on vehicle range and emissions. Furthermore, the paper explores advanced technologies currently being developed by various industries to enhance processing speeds and reduce energy consumption in autonomous vehicles.
Concept Mapping STI/HIV Prevention and Condom Use among Young African American Adults
(2024-06-14) Carmack, Chakema; Nganga, Sarah; Ahmed, Eisha; Coleman, Taylor
Theory-based HIV prevention programs have resulted in increased condom use, which remains the best method for the prevention of sexually transmitted infections (STIs) among sexually active heterosexual individuals. Particularly, the integrative model of behavior prediction theorizes that attitudes, norms, self-efficacy, and socioenvironmental factors influence intention and behavior and has been useful in understanding STI risk among adolescents. However, more research is needed regarding young African American adults. Given the increased freedom and decision-making independence afforded to young adults compared to adolescents, it is important to consider the STI/human immunodeficiency virus (HIV) prevention messages that would resonate with them, particularly regarding condom use. The present study sought to explore how attitudes, subjective norms, self-efficacies, and socioenvironmental factors may influence condom use and STI/HIV prevention, as conceptualized by the participants. We conducted a group-based concept map, a systems-thinking mixed methodology that resulted in a geospatial map reflecting the conceptualizations of the participants. Self-identified young heterosexual African American adults (N = 43) aged 20–26 engaged in an interactive concept mapping procedure in order to “map out” their overarching concepts about STI/HIV risk and condom use. Seven overall conceptual domains emerged: self-efficacy for partner communication, condom use self-efficacy, social media/sociocultural influences, condom use/STI knowledge, condom use cons, condom use pros, and subjective and social norms about condom use. We presented the concept map and discussed the conceptual interpretations and the relationships among the overarching concepts. We also discussed how the social environment, including the social media environment, was conceptualized regarding STI/HIV risk and prevention among young African American adults. Concept mapping can be viewed as a way to determine worthwhile messages for intervention development. The findings may provide information for prevention programs aimed at reducing the incidence of STIs among young adult heterosexual persons within African American communities.
Social Determinants of Health and Other Predictors in Initiation of Treatment with CDK4/6 Inhibitors for HR+/HER2− Metastatic Breast Cancer
(2024-06-07) Goyal, Ravi K.; Candrilli, Sean D.; Abughosh, Susan; Chen, Hua; Holmes, Holly M.; Johnson, Michael L.
In hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2−) metastatic breast cancer (MBC), cyclin-dependent kinase 4/6 inhibitors (CDK4/6is) have replaced endocrine therapy alone as the standard of care; however, several barriers to treatment initiation still exist. We assessed social determinants of health (SDOH) and other factors associated with the initiation of CDK4/6i for HR+/HER2− MBC in the Medicare population. Using a retrospective cohort design, patients aged ≥65 years and diagnosed during 2015–2017 were selected from the SEER-Medicare database. Time from MBC diagnosis to first CDK4/6i initiation was the study outcome. The effect of SDOH measures and other predictors on the outcome was assessed using the multivariable Fine and Gray hazard modeling. Of 752 eligible women, 352 (46.8%) initiated CDK4/6i after MBC diagnosis (median time to initiation: 27.9 months). In adjusted analysis, SDOH factors significantly associated with CDK4/6i initiation included high versus low median household income (HHI) (hazard ratio [HR] = 1.70; 95% CI = 1.03–2.81) and the percentage of population with high versus low Medicare-only coverage (HR = 1.54; 95% CI = 1.04–2.27). In summary, older Medicare patients with HR+/HER2− MBC residing in areas with high median HHI and a high proportion of Medicare-only coverage had higher rates of initiating CDK4/6i, suggesting inequitable access to these novel, effective treatments and a need for policy intervention.
Gratitude Predicts Meaning in Life in Family Caregivers of Persons with Alzheimer’s Disease
(2024-05-30) McGee, Jocelyn Shealy; Polson, Edward C.; Myers, Dennis R.; McClellan, Angela M.; Ke, Weiming; Zhao, Holly Carlson; Meraz, Rebecca
Gratitude is a well-known and researched internal positive psychological resource. Empirical data, however, on the association between gratitude, meaning in life, and burden in family caregivers of persons with Alzheimer’s disease is scant. The aims of this study were to (1) investigate the relationships among these variables in a sample of family caregivers of persons with Alzheimer’s; and (2) determine if gratitude mediates the effects of perceived burden on meaning in life in this population. One-hundred and twenty-six adult family caregivers, most of whom were an intimate partner or adult child of a person with Alzheimer’s, completed the Gratitude Questionnaire-Six Item, the Meaning in Life Questionnaire, the Zarit Burden Inventory, and other relevant measures. A series of OLS regression models, guided by the caregiver stress process model, were conducted. These analyses demonstrated that gratitude was a predictor of the presence of meaning in life among the caregivers in this study even when other key variables were considered. Furthermore, analyses revealed that gratitude fully mediated the effects of caregiver burden on the presence of meaning in life in this sample. Thus, clinicians should consider gratitude as an important internal resource for cultivating meaning in life in this population, especially when caregiver burden is present. Gratitude-bolstering clinical interventions should be further developed and tested as both stand-alone and complimentary additions to empirically supported psychoeducational approaches for supporting health and well-being in this population.
On the Kantorovich Theory for Nonsingular and Singular Equations
(2024-05-28) Argyros, Ioannis K.; George, Santhosh; Regmi, Samundra; Argyros, Michael I.
We develop a new Kantorovich-like convergence analysis of Newton-type methods to solve nonsingular and singular nonlinear equations in Banach spaces. The outer or generalized inverses are exchanged by a finite sum of linear operators making the implementation of these methods easier than in earlier studies. The analysis uses relaxed generalized continuity of the derivatives of operators involved required to control the derivative and on real majorizing sequences. The same approach can also be implemented on other iterative methods with inverses. The examples complement the theory by verifying the convergence conditions and demonstrating the performance of the methods.
Abraham’s Faith: Both the Aesthetic and the Ethical in Fear and Trembling
(2024-05-24) Westfall, Joseph
In this paper, I examine Johannes de Silentio’s presentation of the faith of Abraham, deriving therefrom a new way of conceiving his notion of faith as a paradoxical co-inhabiting of both the aesthetic and the ethical stages, rather than as a rejection, synthesis, or overcoming of them. Relying largely upon Silentio’s account of Abraham’s faith as anxious but not doubting, I argue that the interpretations of Fear and Trembling by Alastair Hannay and Mark C. Taylor fail to account for some essential aspects of Silentio’s depiction. I conclude that faith, as it is described in Fear and Trembling, cannot be philosophically understood as it is not an object for thought but an existential perspective one lives.
Cash Rules Everything around Me: Investigating Craft Beer Drinkers Purchase Decisions during Inflationary Period
(2024-05-17) Taylor, Scott; Taylor, D. Christopher
Since March 2020, there have been multiple outside influences negatively impacting the U.S. craft beer industry from COVID-19 to inflation all leading up to increased prices for consumers. However, to date, research has not investigated consumer sentiment toward increased prices and their willingness to continue paying increased prices for beer from various outlets. The current study provides an initial assessment of craft beer consumers’ purchase behaviors for on(own)- and off-premise consumption given the impacts of COVID-19 and the recent economic situation. Past research has indicated that increased prices tend to lead to decreased purchases of beer (and alcohol in general). Results of the current online survey of craft beer drinkers mostly align with past findings, as nearly half of the 350 participants in this study indicated that they had decreased their consumption of craft beer away from home. Relatedly, respondents indicated a relatively low willingness to pay price increases for craft beer consumed on-premise (own-premise) or off-premise.
Parameter Choice Strategy That Computes Regularization Parameter before Computing the Regularized Solution
(2024-05-13) George, Santhosh; Padikkal, Jidesh; Kunnarath, Ajil; Argyros, Ioannis K.; Regmi, Samundra
The modeling of many problems of practical interest leads to nonlinear ill-posed equations (for example, the parameter identification problem (see the Numerical section)). In this article, we introduce a new source condition (SC) and a new parameter choice strategy (PCS) for the Tikhonov regularization (TR) method for nonlinear ill-posed problems. The new PCS is introduced using a new SC to compute the regularization parameter (RP) before computing the regularized solution. The theoretical results are verified using a numerical example.
Understanding Pharmacy Students’ Preparedness towards Counseling over Cannabis Use Disorder
(2024-05-13) Ganna, Sourab; Daggolu, Jerusha; Sansgiry, Sujit S.
The rise in cannabis use prompts significant concerns regarding pharmacy students’ abilities to counsel patients over cannabis use disorder. This study aims to understand pharmacy students’ preparedness to counsel patients with cannabis use disorder (CUD) and evaluate the relationship between knowledge, attitudes towards medical cannabis (MC) and recreational cannabis (RC), and behavior intention (BI) to counsel over CUD. A cross-sectional survey was administered to pharmacy students. Descriptive analyses of sample characteristics were assessed with the t-test and one-way ANOVA test. Pearson correlation and linear regression were conducted, measuring the strength and direction of relationships. The average scores for knowledge, attitudes towards MC use and RC, and behavioral intention were 81% (SD 16%), 4.13 (SD 0.75), 3.28 (0.80), and 2.74 (1.00). Significant correlations were observed between knowledge–attitudes toward MC, knowledge–attitudes towards RC, and attitudes towards RC–behavioral intentions. Linear regression indicated attitudes towards MC use and RC, academic year, awareness of MC use legality, obtained knowledge, and past patient interaction were significantly associated with behavioral intention on confidence in counseling over CUD. There is a gap in students’ behavioral intention to counsel. These findings emphasize the importance of ample preparation that enables student pharmacists to address patient needs related to cannabis use confidently.
Further Examination of the Pulsed- and Steady-Pedestal Paradigms under Hypothetical Parvocellular- and Magnocellular-Biased Conditions
(2024-04-30) Song, Jaeseon; Breitmeyer, Bruno G.; Brown, James M.
The pulsed- and steady-pedestal paradigms were designed to track increment thresholds (ΔC) as a function of pedestal contrast (C) for the parvocellular (P) and magnocellular (M) systems, respectively. These paradigms produce contrasting results: linear relationships between ΔC and C are observed in the pulsed-pedestal paradigm, indicative of the P system’s processing, while the steady-pedestal paradigm reveals nonlinear functions, characteristic of the M system’s response. However, we recently found the P model fits better than the M model for both paradigms, using Gabor stimuli biased towards the M or P systems based on their sensitivity to color and spatial frequency. Here, we used two-square pedestals under green vs. red light in the lower-left vs. upper-right visual fields to bias processing towards the M vs. P system, respectively. Based on our previous findings, we predicted the following: (1) steeper ΔC vs. C functions with the pulsed than the steady pedestal due to different task demands; (2) lower ΔCs in the upper-right vs. lower-left quadrant due to its bias towards P-system processing there; (3) no effect of color, since both paradigms track the P-system; and, most importantly (4) contrast gain should not be higher for the steady than for the pulsed pedestal. In general, our predictions were confirmed, replicating our previous findings and providing further evidence questioning the general validity of using the pulsed- and steady-pedestal paradigms to differentiate the P and M systems.
A Comprehensive Summary of the Application of Machine Learning Techniques for CO2-Enhanced Oil Recovery Projects
(2024-04-29) Du, Xuejia; Salasakar, Sameer; Thakur, Ganesh
This paper focuses on the current application of machine learning (ML) in enhanced oil recovery (EOR) through CO₂ injection, which exhibits promising economic and environmental benefits for climate-change mitigation strategies. Our comprehensive review explores the diverse use cases of ML techniques in CO₂-EOR, including aspects such as minimum miscible pressure (MMP) prediction, well location optimization, oil production and recovery factor prediction, multi-objective optimization, Pressure–Volume–Temperature (PVT) property estimation, Water Alternating Gas (WAG) analysis, and CO₂-foam EOR, from 101 reviewed papers. We catalog relative information, including the input parameters, objectives, data sources, train/test/validate information, results, evaluation, and rating score for each area based on criteria such as data quality, ML-building process, and the analysis of results. We also briefly summarized the benefits and limitations of ML methods in petroleum industry applications. Our detailed and extensive study could serve as an invaluable reference for employing ML techniques in the petroleum industry. Based on the review, we found that ML techniques offer great potential in solving problems in the majority of CO₂-EOR areas involving prediction and regression. With the generation of massive amounts of data in the everyday oil and gas industry, machine learning techniques can provide efficient and reliable preliminary results for the industry.
Enablers and Inhibitors to Implementing Tobacco Cessation Interventions within Homeless-Serving Agencies: A Qualitative Analysis of Program Partners’ Experiences
(2024-06-06) Martinez Leal, Isabel; Siddiqi, Ammar D.; Rogova, Anastasia; Britton, Maggie; Chen, Tzuan A.; Williams, Teresa; Casey, Kathleen; Sanchez, Hector; Reitzel, Lorraine R.
Despite the high tobacco use rates (~80%) and tobacco-related cancers being the second leading cause of death among people experiencing homelessness within the United States, these individuals rarely receive tobacco use treatment from homeless-serving agencies (HSAs). This qualitative study explored the enablers and inhibitors of implementing an evidence-based tobacco-free workplace (TFW) program offering TFW policy adoption, specialized provider training to treat tobacco use, and nicotine replacement therapy (NRT) within HSAs. Pre- and post-implementation interviews with providers and managers (n = 13) pursued adapting interventions to specific HSAs and assessed the program success, respectively. The organizational readiness for change theory framed the data content analysis, yielding three categories: change commitment, change efficacy and contextual factors. Pre- to post-implementation, increasing challenges impacted the organizational capacity and providers’ attitudes, wherein previously enabling factors were reframed as inhibiting, resulting in limited implementation despite resource provision. These findings indicate that low-resourced HSAs require additional support and guidance to overcome infrastructure challenges and build the capacity needed to implement a TFW program. This study’s findings can guide future TFW program interventions, enable identification of agencies that are well-positioned to adopt such programs, and facilitate capacity-building efforts to ensure their successful participation.
Experimental Study on Pulsed Plasma Stimulation and Matching with Simulation Work
(2024-05-31) Khalaf, Mina; Soliman, M.; Farouq-Ali, S. M.; Cipolla, Craig; Dusterhoft, Ron
Plasma stimulation is a form of waterless fracturing as it requires that only the wellbore be filled with an aqueous fluid. The technique creates multiple fractures propagating in different directions around the wellbore. The intent of this paper is to present an experimental and numerical investigation of the degree of competitiveness of plasma stimulation with hydraulic fracturing, especially in the case of stimulating tight formation. Several cases were run experimentally. The samples included limestone and sandstone to investigate plasma fracturing in different rock types. In addition, the main goal of the experiments was to study the creation of fracture(s) under confining stresses, the type of rock, the amount of electrical energy used in the experiment, and the length of the wire to generate the plasma reaction. A laboratory plasma equipment was designed and used to accomplish the experimental work. The experiments were then numerically matched using a finite element numerical simulator, HOSS developed by LANL (Los Alamos National Lab). HOSS was developed to simulate high-strain-rate fractures such as those created by plasma stimulation. It accounts for mixed-mode fracture mechanics which are tensile and shear fractures. The simulator governing equations obey the conservation of mass and momentum in a solid-mechanics sense and account for the nonlinear deformation of rock material. The matching of the experiment allowed us to validate the HOSS simulation of the process and showed that the numerical results are in good agreement with the experimental work. Using the HOSS simulator, we also investigated the effect of higher energy levels and/or short release time on a cement rock model. The pressure profile that is developed due to the energy release can vary in the peak pressure and the release time. The results showed that the plasma fracturing technique is an effective stimulation method in sandstone and limestone. Plasma fractures were developed in the rock samples and extended from the sample wellbore to the outer boundaries. The shape of the pressure pulse has an impact on the developed fractures. Moreover, the effect of plasma stimulation on natural fractures was studied numerically. It was found that natural fractures can arrest the plasma-generated fractures that propagate from the wellbore to the outer boundaries. However, new fractures may develop in the rock starting from the natural fracture tips.
Prevalence of Metabolic Syndrome Based on Activity Type and Dietary Habits in Extremely Low-Income Individuals
(2024-05-29) Su, Kunxia; Kim, Yonghwan; Park, Yoonjung
A high prevalence of metabolic syndrome (MS) and cardiovascular disease among low-income individuals has often been reported. However, there is still a lack of research on the relationship between basic livelihood security (BLS) and MS. This study investigated the prevalence of MS according to activity type, dietary habits, and the nutrient intake characteristics of individuals receiving BLS. Data from 14,803 men and 20,299 women were analyzed to assess the association between receiving BLS and MS. The associations between MS and various factors were analyzed separately in men and women by logistic regression analysis. In this cohort, 5.9% of men and 6.8% of women received BLS; of these, 46.9% and 47.7% had MS, respectively. High caloric intake, low-frequency breakfast consumption, and no nutritional education were associated with MS in both men and women. Among those with a low-frequency walking habit and strength training activity type, MS increased by 1.58 and 1.57 times in men and by 1.47 and 2.16 times in women, respectively. Men who were sedentary for 8 h or more had an increased risk of MS, but there was no association between these in women. BLS nutritional intake characteristics were high in carbohydrates and fat and low in dietary fiber and vitamin C (p < 0.05). In conclusion, establishing a healthy eating pattern through nutritional education and increasing walking and strength training may reduce the risk of MS.
Designing a Novel Hybrid Technique Based on Enhanced Performance Wideband Millimeter-Wave Antenna for Short-Range Communication
(2024-05-18) Islam, Tanvir; Hussain, Dildar; Alsunaydih, Fahad N.; Alsaleem, Fahd; Alhassoon, Khaled
This paper presents the design of a performance-improved 4-port multiple-input–multiple-output (MIMO) antenna proposed for millimeter-wave applications, especially for short-range communication systems. The antenna exhibits compact size, simplified geometry, and low profile along with wide bandwidth, high gain, low coupling, and a low Envelope Correlation Coefficient (ECC). Initially, a single-element antenna was designed by the integration of rectangular and circular patch antennas with slots. The antenna is superimposed on a Roger RT/Duroid 6002 with total dimensions of 17 × 12 × 1.52 mm³. Afterward, a MIMO configuration is formed along with a novel decoupling structure comprising a parasitic patch and a Defected Ground Structure (DGS). The parasitic patch is made up of strip lines with a rectangular box in the center, which is filled with circular rings. On the other side, the DGS is made by a combination of etched slots, resulting in separate ground areas behind each MIMO element. The proposed structure not only reduces coupling from −17.25 to −44 dB but also improves gain from 9.25 to 11.9 dBi while improving the bandwidth from 26.5–30.5 GHz to 25.5–30.5 GHz. Moreover, the MIMO antenna offers good performance while offering strong MIMO performance parameters, including ECC, diversity gain (DG), channel capacity loss (CCL), and mean effective gain (MEG). Furthermore, a state-of-the-art comparison is provided that results in the overperforming results of the proposed antenna system as compared to already published work. The antenna prototype is also fabricated and tested to verify software-generated results obtained from the electromagnetic (EM) tool HFSS.
Sex Differences in the Influence of Relationships on Adolescent Offending
(2024-05-17) Zedaker, Sara; Fansher, Ashley K.; Goodson, Amanda
The impact of romantic relationships during the adolescent period has received significantly less attention in the literature compared to the influence of romantic relationships during adulthood. Specifically, how these influences may differ between females and males. As such, the current study uses four waves of data from the Pathways to Desistance study to examine how elements of romantic relationships, including relationship quality, monitoring, and antisocial influence, affect adolescent delinquent behaviors by sex. Results indicated several important findings regarding the desistance effects of romantic relationship quality, monitoring, and antisocial influence on adolescent violent and non-violent offending, and these varied widely by sex. Limitations, future research, and policy recommendations are discussed.
Identification of Genes Crucial for Biological Processes in Breast Cancer Liver Metastasis Relapse
(2024-05-16) Kwok, Tyler; Yeguvapalli, Suneetha; Chitrala, Kumaraswamy Naidu
Breast cancer, when advancing to a metastatic stage, involves the liver, impacting over 50% of cases and significantly diminishing survival rates. Presently, a lack of tailored therapeutic protocols for breast cancer liver metastasis (BCLM) underscores the need for a deeper understanding of molecular patterns governing this complication. Therefore, by analyzing differentially expressed genes (DEGs) between primary breast tumors and BCLM lesions, we aimed to shed light on the diversities of this process. This research investigated breast cancer liver metastasis relapse by employing a comprehensive approach that integrated data filtering, gene ontology and KEGG pathway analysis, overall survival analysis, identification of the alteration in the DEGs, visualization of the protein–protein interaction network, Signor 2.0, identification of positively correlated genes, immune cell infiltration analysis, genetic alternation analysis, copy number variant analysis, gene-to-mRNA interaction, transcription factor analysis, molecular docking, and identification of potential treatment targets. This study’s integrative approach unveiled metabolic reprogramming, suggesting altered PCK1 and LPL expression as key in breast cancer metastasis recurrence.
EPSOM-Hyb: A General Purpose Estimator of Log-Marginal Likelihoods with Applications in Probabilistic Graphical Models
(2024-05-15) Chuu, Eric; Niu, Yabo; Bhattacharya, Anirban; Pati, Debdeep
We consider the estimation of the marginal likelihood in Bayesian statistics, with primary emphasis on Gaussian graphical models, where the intractability of the marginal likelihood in high dimensions is a frequently researched problem. We propose a general algorithm that can be widely applied to a variety of problem settings and excels particularly when dealing with near log-concave posteriors. Our method builds upon a previously posited algorithm that uses MCMC samples to partition the parameter space and forms piecewise constant approximations over these partition sets as a means of estimating the normalizing constant. In this paper, we refine the aforementioned local approximations by taking advantage of the shape of the target distribution and leveraging an expectation propagation algorithm to approximate Gaussian integrals over rectangular polytopes. Our numerical experiments show the versatility and accuracy of the proposed estimator, even as the parameter space increases in dimension and becomes more complicated.
3D VSP Imaging Using DAS Recording of P- and S-Waves in Vertical and Lateral Well Sections in West Texas
(2024-05-11) Wang, Yin-Kai; Stewart, Robert R.
A 3D vertical seismic profiling (VSP) survey was acquired using a distributed acoustic sensing (DAS) system in the Permian Basin, West Texas. In total, 682 shot points from a pair of vibroseis units were recorded using optical fibers installed in a 9000 ft (2743 m) vertical part and 5000 ft (1524 m) horizontal reach of a well. Transmitted and reflected P, S, and converted waves were evident in the DAS data. From first-break P and S arrivals, we found average P-wave velocities of approximately 14,000 ft/s (4570 m/s) and S-wave velocities of 8800 ft/s (3000 m/s) in the deep section. We modified the conventional geophone VSP processing workflow and produced P–P reflection and P–S volumes derived from the well’s vertical section. The Wolfcamp formation can be seen in two 3D volumes (P–P and P–S) from the vertical section of the well. They cover an area of 3000 ft (914 m) in the north–south direction and 1500 ft (460 m) in the west–east direction. Time slices showed coherent reflections, especially at 1.7 s (~11,000 ft), which was interpreted as the bottom of the Wolfcamp formation. Vp/Vs values from 2300 ft (701 m) –8800 ft (2682 m) interval range were between 1.7 and 2.0. These first data provide baseline images to compare to follow-up surveys after hydraulic fracturing as well as potential usefulness in extracting elastic properties and providing further indications of fractured volumes.

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