Ex Situ Tribological and Electro-chemical analysis of Aluminium

Aluminium sample coupon is evaluated for electro-chemical, tribological and microstructural study under selected test conditions. Aluminium is a light-weight material chiefly preferred in fields like automobile, aerospace, marine and satellite domestic appliances etc. Moreover, due to its specific characteristics, it plays a crucial role in industries and research fields. In the present work, the ex situ tribological (wear test), electrochemical (corrosion test), mechanical (microhardness test) and microstructural (nodularity percentage) behaviours of Aluminum sample is presaged. The test results reveal that, when experiment advance, with respect to time the wear rate increases, frictional force is decreased and pin temperature increased. The corrosion test is held on specimen coupon in two modes, before and after wear test, and observed that the corrosion rate gets improved on specimen after wear test. Nodularity analysis also express that the nodularity percentage is increased by 5%. Before wear test, the percentage of accepted count to total count of nodules on texture is 65.18%, while the percentage after wear test is found to be 70.29%. The Vickers Microhardness analysis exhibits the hardness value as 160 HV on Vickers Hardness Scale.

Validity of Self-Reported Sexual Function Scales: A Comparison Study with Auxiliary-Reporting (Preprint)

BACKGROUND Sexual function scales are widely used in self-diagnosis and web-based surveys, but their validity has not been evaluated. OBJECTIVE To explore the validity of self-reported sexual function scales. METHODS The participants who visited our hospital from June 1, 2020 to April 1, 2021 filled two questionnaires. The first, self-report version (SRV), was filled individually. The second, auxiliary-report version (ARV) was filled after explanation and aid from a researcher. The ARV was used as the standard, and the classification was based on age, occupation, education, Premature Ejaculation Diagnostic Tool (PEDT), International Index for Erectile Function (IIEF-6), and sexual frequency. The number of misdeclarations, overestimations, underestimations, false-positive, and false-negative rates of Erection Hardness Scale (EHS), IIEF-6, Masturbation Erection Index (MEI), and PEDT in the SRV were evaluated. The intraclass correlation coefficient, Spearman correlation, and Bland-Altman plot were used to assess consistency. RESULTS A total of 322 patients who visited our hospital were included. The SRV error rate was higher for participants over 40 years of age. The remaining categories had no effect on the error rate of the SRV. In addition, as individuals, participants were more likely to overestimate the severity of their disease in the SRV, consistent with a false-positive rate. Overall, there was consistency between the two questionnaires. CONCLUSIONS The self-reporting of EHS, IIEF-6, MEI, and PEDT by participants was valid. These can help patients to effectively and quickly reach conclusions in a cost-friendly manner. However, misdiagnoses are possible. CLINICALTRIAL The present study protocol was reviewed and approved by the institutional review board of Third Affiliated Hospital of Sun Yat-sen University (Reg. No. [2021]02-249-01).

The Characteristics of Kasiro Shale and Its Implication to Oil Shale Identification at The Batang Asai, Sarolangun, Jambi

The necessity of oil and natural gas from fossil energy sources in Indonesia is increasing over time, whereas oil and gas reserves generated from conventional reservoirs are decreasing. To anticipate gas shortages, exploration of unconventional resources is needed. The main focus of the rock formation in this research is the Tertiary Miocene Kasiro Formation. This formation is dominated by Shale and Claystone. Shale characteristic from the megascopic aspect of Tertiary Miocene Kasiro Formation in the research area have fissile structure with soft to hard in hardness scale of shale. Shale characteristic from microscopic aspect based on petrography, SEM (Scanning Electron Magnetic) and XRD (X-Ray Diffraction) show illite as main clay mineral. Other clay minerals such as montmorilonite and kaolinite also can be found as well as some important mineral like quartz, chlorite, biotite, alunite and diaspore. Shale diagenesis rate of the Tertiary Miocene Kasiro Formation is defined based on the presence of some clay mineral like illite, kaolinite and montmorillonite. Based on the result of SEM and XRD analyses, the shale diagenesis in the research area can be classified as early mesodiagenesis. The diagenesis rate also can show that oil maturity in the Kasiro shale can be classified as immature to semi mature. Based on the shale characteristic, the Kasiro shale was deposited in a weak current mechanism and based on the presence of alginite, the shale was deposited within lacustrine environment. The lacustrine environment have a characteristic of low oxygen rate that can be seen with the presence of mollusk fossil such as viviparous that indicating a fresh water and weak current enviroment.

Experimental and numerical investigation of cutting forces during turning of cylindrical AISI 4340 steel specimens

Cutting forces play a significant role in machining because they directly affect the mechanics of machining, the energy requirements, and the tool stability required. In this study, the cutting forces occurring during the turning of AISI 4340 material with 30 Rockwell C hardness scale have been analyzed both experimentally and numerically. Many types of research have been conducted via 2-D simulation using the finite element analysis method. In other words, in most studies, the workpiece was modeled as a flat specimen. Therefore, this paper presents a real 3-D turning simulation model using cylindrical specimens. The cutting forces were measured using a Kistler 9129AA model piezoelectric dynamometer. The ABAQUS/Explicit finite element method was used, and a model by Johnson and Cook was assigned as a material model in the numerical analysis. A new PVD AlTiN coated carbide insert was incorporated to prevent wear. Experimental results obtained from cutting tests were compared with numerical results to establish the accuracy of the FEM. It was observed that experimental and numerical results overlapped each other. Thus, this method can be used directly in the industry to reduce high processing costs.

Characterization of barite reserves in Nigeria for use as weighting agent in drilling fluid

Successful drilling operations are dependent on the properties of the drilling fluid used to drill wells. Barite is used as a weighting agent during the preparation of drilling fluid. Over the years, oil and gas industry in Nigeria has been depending mainly on imported barite for drilling operations, whereas the country has huge deposits of barite. There is the need to assess the properties of the locally sourced barite for their suitability in drilling fluid formulation. This study presents the local processing methods of barite and examines the crude and on-the-site processed barite’s physio-chemical properties. These parameters were compared with American Petroleum Institute and Department of Petroleum Resources standards. XRD results show that on-the-site beneficiated barite has 87.79% BaSO4, 6.66% silica, 0.03% total soluble salt, 1.39% Fe2O3, and 1.603% heavy metals. Chemical analysis indicated that the pH, moisture content, metallic content such as Ca, Pb, Zn, Mg, Cu, and Cd minerals, and extractable carbonates were within the standard specified for usage as a drilling fluid weighting agent. The analysed crude barite samples were basic, within the pH of 8.3 and 8.6. Locally processed barite has lower Fe, Pb, Cd, and Cu content compared to industrially accepted barite. The specific gravity increased from 4.02 ± 0.07 to 4.15 ± 0.13, and the hardness reduced potentially from 5 Mohr to 3.5 Mohr on the hardness scale. The amount of impurities was sufficiently low, and the specific gravity of the samples improved to meet the needs of any drilling operation and compare favourably with industrially accepted barite.

Shear wave elastography as a new, non-invasive diagnostic modality for the diagnosis of penile elasticity: a prospective multicenter study

Objective: Shear wave elastosonography (SWE) could be used to evaluate the elasticity of penile tissue. Few studies in the literature, however, have investigated its use in patients with erectile dysfunction (ED) or have attempted to correlate findings with International Index of Erectile Function (IIEF-5) scores. The primary aim of this study was to evaluate the characteristics of erectile tissue using SWE and to determine possible relationships with IIEF-5 and Erection Hardness Scale (EHS) scores. The secondary aim was to establish a cut-off SWE examination value over which cavernous tissue stiffness could contribute to a subsequent organic alteration. Methods: This prospective study included male patients 18−80 years of age who attended two general andrology clinics and underwent SWE. Subjects were divided into groups according to IIEF-5 score, and correlations between SWE and IIEF-5 and EHS questionnaire scores were explored. Results: A total of 270 subjects (mean age 46.7 ± 16.9 years) were included. ED was reflected by low IIEF-5 and EHS scores and a decrease in the mean elasticity of the corpora cavernosa according to SWE, although the difference between the left and right corpora cavernosa was not statistically significant. No statistically significant correlation was found between measurements of the corpora cavernosa (in kPa) and age. The optimal cut-off identified was 24.75 kPa. Conclusion: Results demonstrated that the mean elasticity of the corpora cavernosa according to SWE was correlated with IIEF-5 score and EHS score.

An estimate of the pitting strength of steel materials

A single expression for estimating the nominal pitting strength of steel materials, based on surface hardness, is developed from first principles for a reliability of 99% at 107 load cycles. It requires the hardness values to be measured in Vicker's hardness scale. The expression may be used for any steel material processed by hot rolling, cold drawing, quenching and tempering or case-hardening. The formulation incorporates a nominal design factor at 99% reliability which is estimated from a probabilistic model based on the lognormal probability density function. Pitting strength estimates from the expression are compared with those of American Gear Manufacturers Association (AGMA) estimates and data from other sources as indicated in Tables 3 and 4. The expression predicts lower values at low hardness but higher values at high hardness. The variance is between - 15.21% and 10.13% for through-hardened steels. For case-hardened steels, the variances range from 14.23% to 20.26% between the estimates and available data. These variances appear to be reasonable considering the many factors involved in pitting resistance. The main advantage of this study is that pitting strength of new steel materials may be estimated for initial design sizing without long and costly contact fatigue testing which of course is necessary for design validation. Also, the estimation method developed may be applied to other materials, metallic and non-metallic. Suggestions are made for estimating some pertinent pitting strength adjustment factors when considering field or service pitting strength.

Standardization of penile hemodynamic evaluation through color duplex-doppler ultrasound

SUMMARY INTRODUCTION: The vascular evaluation of the erectile function through Color Duplex-Doppler Ultrasound (CDDU) of the penis can benefit the therapeutic decision-making process. Unfortunately, there is no standard procedure for CDDU conduction, a fact that results in high result-interpretation variability. OBJECTIVE: The aims of this review are to promote greater standardization during CDDU of the penis and discuss the fundamental principles for its accurate conduction. METHODS: CDDU is initially conducted with the penis in the flaccid state; the whole penis must be assessed (images at B mode) with a high-frequency linear transducer (7.5-18 MHz). Intracavernous injection of vasodilating agents (prostaglandin E1, papaverine, phentolamine) is performed to induce a rigid erection. Serial measurements at different times should be taken during the CDDU session and penile rigidity must be assessed in each evaluation. RESULTS: It is important to monitor the erection response after the vasoactive agent (hardness scale), and scanning during the best-quality erection should be contemplated. Manual self-stimulation, audiovisual sexual stimulation (AVSS), and vasoactive agent re-dosing protocols must be taken into account to reduce the influence of psychogenic factors and to help the patient to get the hardest erection possible. Such measurements contribute to the maximal relaxation of the erectile tissue, so the hemodynamic parameters are not underestimated. CONCLUSIONS: CDDU is a relevant specialized tool to assess patients with erectile dysfunction; therefore, this guideline will help to standardize and establish uniformity in its conduction and interpretation, taking into consideration the complexity and heterogeneity of CDDU evaluations of the penis.