Prime Ideals in Right Complement Bounded Rings

Hamed E. A BULKHEIR ..et al. KYUNGPOOK UNIVERSITY 1996 Kyungpook mathematical journal Vol.36 No.1

A ring R is right complement bounded (strongly right bounded) if every nonzero right complement (right ideal) contains a nonzero two-sided ideal. For these rings we discuss the set of nilpotent elements and show that the right singular ideal Z_(n) and its closure Z_(2) are completely prime. Furthermore the inessential prime ideals and the inessential maximal right ideals are described. A decomposition of a right continuous strongly right bounded ring with unity and no infinite sets of orthogonal central idempotents is given.

Common conditions associated with mandibular canal widening: A literature review

Hamed Mortazavi,Maryam Baharvand,Yaser Safi,Kazem Dalaie,Mohammad Behnaz,Fatemeh Safari 대한영상치의학회 2019 Imaging Science in Dentistry Vol.49 No.2

Purpose: The aim of this study was to review the common conditions associated with mandibular canal widening. Materials and Methods: General search engines and specialized databases including Google Scholar, PubMed, PubMed Central, Science Direct, and Scopus were used to find relevant studies by using the following keywords: “mandibular canal,” “alveolar canal,” “inferior alveolar nerve canal,” “inferior dental canal,” “inferior mandibular canal,” “widening,” “enlargement,” “distension,” “expansion,” and “dilation.” Results: In total, 130 articles were found, of which 80 were broadly relevant to the topic. We ultimately included 38 articles that were closely related to the topic of interest. When the data were compiled, the following 7 lesions were found to have a relationship with mandibular canal widening: non-Hodgkin lymphoma, osteosarcoma, schwannoma, neurofibroma, vascular malformation/hemangioma, multiple endocrine neoplasia syndromes, and perineural spreading or invasion. Conclusion: When clinicians encounter a lesion associated with mandibular canal widening, they should immediately consider these entities in the differential diagnosis. Doing so will help dentists make more accurate diagnoses and develop better treatment plans based on patients’ radiographs.

Evaluation of the serum sex hormones levels and alkaline phosphatase activity in rats’ testis after administering of berberine in experimental varicocele

Hamed Najaran,Hassan Hassani Bafrani,Hamid Rashtbari,Fatemeh Izadpanah,Mohammad Reza Rajabi,Hamed Haddad Kashani,Abouzar Mohammadi 경희대학교 융합한의과학연구소 2019 Oriental Pharmacy and Experimental Medicine Vol.19 No.2

Current study was aimed to investigate the protective effect of berberine (BB) on the serum gonadotropin-releasing hormone (GnRH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), inhibin B (INHB), testosterone (T) and alkaline phosphatase (Alk-p) activity in the testis of experimental varicocele-induced animals. For the current objective, 30 mature-male Wistar rats were randomly divided into control (n = 6 rats), control-sham (n = 6 rats) and experimental groups (n = 18 rats). The animals in the experimental groups were undergone experimental varicocele and simple laparotomy was conducted in control-sham group. 60 days after varicocele (VCL) induction the experimental group subdivided into: nontreated VCL-induced and 50 mg/kg and 100 mg/kg BB-treated groups (intra-peritoneally). Following 60 days, the animals were euthanized and serum levels of testosterone and testicular activity of alkaline phosphatase were measured. Non-treated VCL-induced animals indicated a significant (P < 0.05) reduction in serum levels of T and INHB and a remarkable (P < 0.05) increase in GnRH, FSH, LH and Alk-p activity compared to control and control-sham groups. Insignificant changes were found between control and control-sham groups. Meanwhile, each BB administered group showed a remarkable (P < 0.05) increase in serum levels of T and INHB and a significant (P < 0.05) decrease in GnRH, FSH, LH and alkaline phosphatase activity in testis tissue. According to the current findings, BB by increasing serum levels of testosterone and INHB increases the testicular endocrine capacity and protects Leydig cell against inflammatory and oxidant injury of varicocele. In addition, BB by inhibiting GnRH, FSH, LH and alkaline phosphatase activity, regulate

Hysteretic performance of SPSWs with trapezoidally horizontal corrugated web-plates

Hamed Kalali,Tadeh Zirakian,Mohammad Hajsadeghi,Farshid J. Alaee 국제구조공학회 2015 Steel and Composite Structures, An International J Vol.19 No.2

Previous research has shown that steel plate shear walls (SPSWs) are efficient lateral force-resisting systems against both wind and seismic loads. A properly designed SPSW can have high initial stiffness, strength, and energy absorption capacity as well as superior ductility. SPSWs have been commonly designed with unstiffened and stiffened infill plates based on economical and performance considerations. Recent introduction and application of corrugated plates with advantageous structural features has motivated the researchers to consider the employment of such elements in stiffened SPSWs with the aim of lowering the high construction cost of such high-performing systems. On this basis, this paper presents results from a numerical investigation of the hysteretic performance of SPSWs with trapezoidally corrugated infill plates. Finite element cyclic analyses are conducted on a series of flat- and corrugated-web SPSWs to examine the effects of web-plate thickness, corrugation angle, and number of corrugation half-waves on the hysteretic performance of such structural systems. Results of the parametric studies are indicative of effectiveness of increasing of the three aforementioned web-plate geometrical and corrugation parameters in improving the cyclic response and energy absorption capacity of SPSWs with trapezoidally corrugated infill plates. Increasing of the web-plate thickness and number of corrugation half-waves are found to be the most and the least effective in adjusting the hysteretic performance of such promising lateral force-resisting systems, respectively. Findings of this study also show that optimal selection of the web-plate thickness, corrugation angle, and number of corrugation half-waves along with proper design of the boundary frame members can result in high stiffness, strength, and cyclic performances of such corrugated-web SPSWs.

Virtual reality: a promising non-pharmacological modality for chronic low back pain management in elderly

Hamed Mortazavi 대한통증학회 2022 The Korean Journal of Pain Vol.35 No.3

Stiffness of bi-modulus hexagonal and diamond honeycombs

Hamed Hatami-Marbini,Milad Rohanifar 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.4

Cellular materials are widely used in various applications because of their low density and high strength. The mechanical behavior of cellular materials under various loading conditions has been investigated. Nevertheless, many of these previous studies assume that the Young’s modulus of constituting struts is the same in tension and compression. The present work first derives analytical expressions for the effective Young’s moduli of hexagonal and diamond lattices composed of struts with different tension and compression moduli under the assumption of small strain deformation. It also uses the finite element method to further investigate the mechanical responses of these lattices. The macroscopic Young’s moduli under both compressive and tensile loads are reported as a function of the ratio of compression and tension moduli of constituting struts. The numerical finite element models are implemented by a user defined material subroutine in ABAQUS. Results reveal that the effective Young’s moduli of periodic hexagonal and diamond lattices significantly decrease with decreasing ratio of compression and tension moduli of the struts. Furthermore, the mechanical behavior of hexagonal lattices composed of struts with different tension–compression moduli is dependent on the loading direction and whether they are compressed or stretched. The unique mechanical properties of bi-modulus cellular materials could find important applications in the automotive and construction industries.

Preparation and field study of combined vaccine against Clostridium perfringens type A and bovine viral diarrhea virus in camels

Hamed Adel Elhelw 대한백신학회 2022 Clinical and Experimental Vaccine Research Vol.11 No.1

Purpose: The key objective of this study was to formulate a local combined inactivated gel adjuvanted vaccine containing bovine viral diarrhea virus (BVDV)-1, BVDV-2 viruses and Clostridium perfringens type A toxoid. The study evaluated its ability to enhance protective active immune response in camels’ calves against these infectious pathogens under field conditions. Materials and Methods: The local BVDV cytopathic strains and a local strain of toxigenic C. perfringens type A were used in vaccines formulation. Vaccines A and B were monovalent vaccines against C. perfringens and both strains of BVDVs, respectively. While the vaccine C was the combined vaccine used against the three agents. All vaccines were adjuvanted with Montanide gel. Sterility, safety, and potency tests were applied on the formulated vaccines. Virus neutralization and toxin anti-toxin neutralization tests were used to evaluate the immune responses. Results: Both monovalent (vaccine A) and combined vaccines (vaccine C) showed a protective level (4.5 and 3 IU/mL, respectively) against C. perfringens from the 2nd-week post-vaccination. The titer declined to 3 and 2 IU/mL, respectively at the 5th-month post-vaccination. The titer against BVDV, the monovalent vaccine (vaccine B) reached the beak (1.95 IU/mL) at the 1st-month post-vaccination and lasted till 6th-month post-vaccination (0.92 and 0.94 IU/mL) for BVDV-1a and BVDV-2, respectively. Conclusion: Vaccination of camels with the combined vaccine adjuvanted by Montanide gel containing C. perfringens type A toxoid and BVDV strains with 6-month intervals is recommended to protect camels safely and efficiently against such infections in the field.

Numerical investigation on punching shear of RC slabs exposed to fire

Hamed Sadaghian,Masood Farzam 사단법인 한국계산역학회 2019 Computers and Concrete, An International Journal Vol.23 No.3

This paper describes the numerical modelling of an interior slab-column connection to investigate the punching shear resistance of reinforced concrete (RC) slabs under fire conditions. Parameters of the study were the fire direction, flexural reinforcement ratio, load levels, shear reinforcement and compressive strength of concrete. Moreover, the efficiency of the insulating material, gypsum, in reducing the heat transferred to the slab was assessed. Validation studies were conducted comparing the simulation results to experiments from the literature and common codes of practice. Temperature dependencies of both concrete and reinforcing steel bars were considered in thermo-mechanical analyses. Results showed that there is a slight difference in temperature endurance of various models with respect to concrete with different compressive strengths. It was also concluded that compared to a slab without gypsum, 10-mm and 20-mm thick gypsum reduce the maximum heat transferred to the slab by 45.8% and 70%, respectively. Finally, it was observed that increasing the flexural reinforcement ratio changes the failure mode from flexural punching to brittle punching in most cases.

Preparation of Polyurethane Silicon Oxide Nanomaterials as a Binder in Leather Finishing

Hamed Elsayed,Rasha Attia,Ola Mohamed,Ahmed Haroun,Nabil El-Sayed 한국섬유공학회 2018 Fibers and polymers Vol.19 No.4

Leather finishing processes using toxic organic solvent based produce volatile organic compounds (VOC), chronic exposure to this chemicals effect on workers' health causing many diseases especially lung cancer. So, polyurethane waterbased was synthesized for application in leather finishing instead of organic solvent based because it’s economic and safety for industry and workers. Preparation of water-based polyurethane (PU) depends on the reaction of polyethylene glycol (PEG, 300) with isophorone diisocyanate (IPDI) and the reaction of IPDI-1,4-butanediol (BDO) together with dimethylolpropionic acid (DMPA), was synthesized by poly-addition polymerization reaction. PU was then modified with different amounts of silicon dioxide nanoparticles (1-5 % SiO2), used as a binder in leather finishing. Leather coated was characterized physically, chemically and thermally by FTIR, GPC, DLS, TEM, SEM and TGA. The results revel that, water vapor permeability (WVP) of leather coated with PU modified with SiO2 showed improvement due to the existence of SiO2 particles which increases the interspaces of the polyurethane coating. SEM showed that when the amount of SiO2 nanoparticles increases, there is uniform nanoparticles accumulated can be observed. EDX prove the presence of Si and O2 elements and the formation of SiO2 nanoparticles. Mechanical properties discussed that tensile strength; tear strength and elongation at break % increase with increase SiO2 concentration until 3 % SiO2 nanoparticles. TGA showed an improvement of thermal stability of coated leather modified with SiO2. Therefore, this study succeeded in preparation of safe, ecofriendly of water-based polyurethane binders which modified with SiO2 for using in leather finishing.

Predicting needlestick and sharps injuries and determining preventive strategies using a Bayesian network approach in Tehran, Iran

Hamed Akbari,Fakhradin Ghasemi 한국역학회 2018 Epidemiology and Health Vol.40 No.-

OBJECTIVES: Recent studies have shown that the rate of needlestick and sharps injuries (NSIs) is unacceptably high in Iranian hospitals. The aim of the present study was to use a systematic approach to predict and reduce these injuries. METHODS: This cross-sectional study was conducted in 5 hospitals in Tehran, Iran. Eleven variables thought to affect NSIs were categorized based on the Human Factors Analysis and Classification System (HFACS) framework and modeled using a Bayesian network. A self-administered validated questionnaire was used to collect the required data. In total, 343 cases were used to train the model and 50 cases were used to test the model. Model performance was assessed using various indices. Finally, using predictive reasoning, several intervention strategies for reducing NSIs were recommended. RESULTS: The Bayesian network HFACS model was able to predict 86% of new cases correctly. The analyses showed that safety motivation and fatigue were the most important contributors to NSIs. Supervisors’ attitude toward safety and working hours per week were the most important factors in the unsafe supervision category. Management commitment and staffing were the most important organizational-level factors affecting NSIs. Finally, promising intervention strategies for reducing NSIs were identified and discussed. CONCLUSIONS: To reduce NSIs, both management commitment and sufficient staffing are necessary. Supervisors should encourage nurses to engage in safe behavior. Excessive working hours result in fatigue and increase the risk of NSIs.