Finite Element Modeling of the Transition Zone between Aggregat and Mortar in Concrete

Visual observations to the Interfacial Transition Zone (ITZ) between aggregate and mortar in concrete showed that this area differs significantly to the bulk mortar, further away from the ITZ. This ITZ has a higher porosity with a dissimilar crystal formation, therefore becoming the weak link in the material. In the past, concrete was seen as a two-phase material consisting of mortar and aggregates only. However, analyzing the material as a three-phase composite including the ITZ, will give a more realistic representation to its behavior. A Finite Element Model (FEM) was developed. The ITZ is modeled as a linkage element having a double spring, perpendicular and parallel to the ITZ surface. The individual load-deformation responses of these springs were obtained from laboratory tested specimens. Non-linearity is generated by evaluating the principal stresses at Gauss points, using the Kupfer-Hilsdorf-Rusch (1969) failure envelope and the CEB-FIB 2010 code. Iteration is conducted by the arc-length method developed by Riks-Wempners. The load-displacement curves resulted by the FEM were validated to laboratory tested specimens curves, to compare its effectiveness and asses the sensitivity of the model

In-space experiment on thermoacoustic convection heat transfer phenomenon-experiment definition

The definition phase of an in-space experiment in thermoacoustic convection (TAC) heat transfer phenomenon is completed and the results are presented and discussed in some detail. Background information, application and potential importance of TAC in heat transfer processes are discussed with particular focus on application in cryogenic fluid handling and storage in microgravity space environment. Also included are the discussion on TAC space experiment objectives, results of ground support experiments, hardware information, and technical specifications and drawings. The future plans and a schedule for the development of experiment hardware (Phase 1) and flight tests and post-flight analysis (Phase 3/4) are also presented. The specific experimental objectives are rapid heating of a compressible fluid and the measurement of the fluid temperature and pressure and the recording and analysis of the experimental data for the establishment of the importance of TAC heat transfer process. The ground experiments that were completed in support of the experiment definition included fluid temperature measurement by a modified shadowgraph method, surface temperature measurements by thermocouples, and fluid pressure measurements by strain-gage pressure transducers. These experiments verified the feasibility of the TAC in-space experiment, established the relevance and accuracy of the experimental results, and specified the nature of the analysis which will be carried out in the post-flight phase of the report

An experimental and analytical investigation of thermoacoustic convection heat transfer in gravity and zero-gravity environments

An experimental and analytical study of Thermoacoustic Convection heat transfer in gravity and zero-gravity environments is presented. The experimental apparatus consisted of a cylinder containing air as a fluid. The side wall of the cylinder was insulated while the bottom wall was allowed to remain at the ambient temperature. The enclosed air was rapidly heated by the top surface which consisted of a thin stainless steel foil connected to a battery pack as the power source. Thermocouples were used to measure the transient temperature of the air on the axis of the cylinder. The ouput of the thermocouples was displayed on digital thermometers and the temperature displays were recorded on film using a high-speed movie camera. Temperature measurements were obtained in the zero-gravity environment by dropping the apparatus in the 2-Seconds Zero-Gravity Drop Tower Facilities of NASA Lewis Research Center. In addition, experiments were also performed in the gravity environment and the results are compared in detail with those obtained under zero-gravity conditions

Global Cancer Statistics 2022: The Trends Projection Analysis

Cancer is one of the most fatal diseases of recent times that causes several deaths every year. The disease variations in different parts of the world, the impact of available medical facilities, and other socio-economic factors have impacted the proper management of this disease. The comparative statistical data of cancer types like breast, prostate, colon, lung, lymph, blood, brain, and kidney cancers can be used to design treatment strategies and therapeutics development. With the advancement of science, several drugs besides diagnostic methods have emerged to control respective cancer and have assisted in curing this disease to some extent. The comparative statistics analysis for cancer about current prevalence is included here to bring a clear framework for the efforts towards future drug development to manage this disease. The availability of new diagnostics and therapeutics and advanced medical facilities in clinics impact cancer statistics. An evaluation of current trends and statistics of cancer pathology vis-à-vis theranostics (diagnostics as well as therapeutics) progress with possible application in clinical settings constitutes the core part of the discussion in this review

A case report of conservative treatment of pelvic organ prolapse in a 40-year-old pregnant woman

BACKGROUND: Pelvic organ prolapse (POP) is a rare event in pregnancy. Genital organs’ prolapse is multi-factorial and can be caused due to weakness of connective tissue and pelvic support muscles and also nerve damage. The purpose of this study is to report a case of conservative treatment of POP in pregnancy.CASE REPORT: A 40-year-old woman with multiparous at week 17 of pregnancy complaining of heaviness, pressure, and mass protrusion from the vagina was referred to the Sayedolshohadaei Hospital in Sanandaj, Iran. On vaginal examination, Grade 3 prolapse based on Pelvic Organ Prolapse Quantification System (POP-Q) was diagnosed. Conservative treatment with pessary was ordered for her and bed rest was recommended followed by personal hygiene. Her pregnancy ended successfully and no complications happened for the mother and the baby.CONCLUSION: Management and treatment of POP in an individualized and separate approach can be adopted based on the patient preferences. Use of pessary to prevent complications would be useful and can be considered as a noninvasive treatment in consulting patients

Development of Cytarabine Prodrugs and Delivery Systems for Leukemia Treatment

Importance of the field: Cytarabine is a polar nucleoside drug used for the treatment of myeloid leukemia and non-Hodgkin’s lymphoma. The drug has a short plasma half-life, low stability, and limited bioavailability. Overdosing of patients with continuous infusions may lead to side effects. Thus, various prodrug strategies and delivery systems have been extensively explored to enhance the half-life, stability, and delivery of cytarabine. Among the recent cytarabine prodrugs, amino acid conjugate ValCytarabine and fatty acid derivative CP-4055 (in phase 3 trials) have been investigated for the treatment of leukemia and solid tumors, respectively. Alternatively, delivery systems of cytarabine have emerged for the treatment of different cancers. The liposomal-cytarabine formulation (DepoCyt®) has been approved for the treatment of lymphomatous meningitis. Areas covered in this review: Various prodrug strategies evaluated for cytarabine are discussed. Then, the review summarizes the drug delivery systems that have been used for more effective cancer therapy. What reader will gain: This review provides in-depth discussion of the prodrug strategy and delivery systems of cytarabine derivatives for the treatment of cancer. The design of cytarabine prodrugs and delivery systems provide insights for designing the next generation of more effective anticancer agents with enhanced delivery and stability. Take home message: Strategies on designing cytarabine prodrug and delivery formulations showed great promise in developing effective anticancer agents with better therapeutic profile. Similar studies with other anticancer nucleosides can be an alternative approach to gaining access to more effective anticancer agents

The First Total Synthesis of (±)-4-methoxydecanoic Acid: A Novel Antifungal Fatty Acid

The hitherto unknown (±)-4-methoxydecanoic acid was synthesized in six steps and in 25% overall yield starting from commercially available 4-penten-1-ol. The title compound demonstrated 17-fold higher antifungal activity (MIC = 1.5 mM) against Candida albicans ATCC 60193 and Cryptococcus neoformans ATCC 66031 when compared to unsubstituted n-decanoic acid. Our results demonstrate that mid-chain methoxylation appears to be a viable strategy for increasing the fungitoxicity of fatty acids

\u3cem\u3eN\u3c/em\u3e-Myristoylglutamic acid derivative of 3′-fluoro-3′-deoxythymidine as an organogel

Designing microbicidal gels of anti-HIV drugs for local application to prevent HIV infection is a subject of major interest. 3′-Fluoro-3′-deoxythymidine (FLT), a nucleoside reverse transcriptase inhibitor (NRTI), was conjugated with a N-myristoylglutamate scaffold. The conjugate showed gelation at 1% (w/w) in different organic solvents, such as toluene, dichloromethane, and chloroform. The gels were opaque and stable at room temperature. The results indicate that myristoyl glutamate derivative of FLT can form an organogel. The gel could have potential application as a topical anti-HIV microbicidal agent