Stability of Intershaft Squeeze Film Dampers

Intershaft squeeze film dampers were investigated for damping of dual rotor aircraft jet engines. It was thought that the intershaft damper would enhance the stability of the rotor-bearing system. Unfortunately, it was determined that the intershaft squeeze film damper was unstable above the engine's first critical speed. Here, a stability analysis of rotors incorporating intershaft squeeze film dampers is discussed. A rotor model consisting of two Jeffcott rotors with two intershaft squeeze film dampers was investigated. Examining the system characteristic equation for the conditions at which the roots indicate an ever-growing unstable motion results in the stability conditions. The cause of the instability is identified as the rotation of the oil in the damper clearance. Several proposed configurations of intershaft squeeze film dampers are discussed, and it is shown that the intershaft dampers are stable supercritically only with a configuration in which the oil film does not rotate

One-stage transanal Swenson procedure for rectosigmoid Hirschsprung’s disease in infants and children

Objective: This study aimed to present the outcome of transanal one-stage Swenson pull-through procedure in the management of rectosigmoid Hirschsprung’s disease (HD).Background: HD is a common cause of intestinal obstruction in pediatric age. Several pull-through procedures have been used to treat this pathology.Patients and methods: Between June 2008 and June 2015, 84 children with biopsy-proven HD underwent transanal one-stage Swenson pull-through procedure. Intraoperative details, postoperative complications, and bowel habits were recorded. Follow-up period ranged from 6 to 42 months.Results: The age at the time of surgery ranged from 3 months to 2 years. The length of the resected aganglionic segment ranged from 12 to 34 cm. The operating time ranged from 72 to 180 min. Postoperative hospital stay ranged from 3 to 6 days. There were no anastomotic leaks, no perianal infection, or postoperative bowel obstruction. Twelve patients (14.28%) developed postoperative enterocolitis. Six patients (7.14%) required a posterior internal sphincter myectomy despite repeated dilatations. All patients had less than four times bowel motions per  day, 3 months after surgery. No voiding disturbances were encountered at the end of the follow-up period and none of the patients complained of recurrent constipation. Six patients developed perianal dermatitis, which was treated conservatively within 3 months after surgery. Anastomotic circumference could not be felt at digital examination in 78 patients 3 months after surgery.Conclusion: One-stage transanal Swenson pull-through procedure is a safe alternative and simpler procedure for rectosigmoid HD with low morbidities and accepted outcome as regards postoperative bowel habits.Keywords: Hirschsprung’s disease, rectosigmoid Hirschsprung’s, Swenson procedure, transanal pull-throug

Using the renal pelvis flap to replace the whole hypoplastic ureter: a preliminary report

Background Hypoplastic ureter is a rare condition usually associated with hypoplastic kidney, and it ends with nephrectomy in most of the cases. Many techniques have been described as ureteric substitutes in the literature. Here, we describe a new technique using the renal pelvis flap to replace the whole hypoplastic ureter in two cases. Objective The aim of this study was to describe a new surgical technique in the management of ureteric hypoplasia.Patients and methods Of the two boys diagnosed antenatally, unilateral hydronephrosis was detected in one boy and a huge renal cyst was present in the other, with evidence of postnatal progressive obstruction necessitating surgical intervention. On exploration, hypoplastic ureter throughout its entire length was an accidental intraoperative finding. The renal pelvis flap was taken and tubularized to replace the entire ureter, and reimplanted into the urinary bladder. This technique was the primary procedure in one case, whereas it was the secondary procedure in the other case after failure of initial trial of pyeloplasty.Results The postoperative period was uneventful with adequate drainage of the renal pelvis in the short-term follow-up (6 and 3 months consecutively).Conclusion The renal pelvis flap is a new feasible alternative procedure for ureteric replacement in a hypoplastic ureter when there is preserved renal parenchyma.Keywords: renal pelvis flap, ureteral hypoplasia, ureteric replacemen

The economic efficiency analysis of some rice mills in Egypt by using DEA and SFA

The main aim of this paper is measuring the economic efficiency of the rice mills public sector in Egypt and comparing the best company according to the economic efficiency. This aim is achieved by estimating the economic efficiency using Data Envelopment Analysis (DEA) and Stochastic Frontier Approach (SFA). This paper is based on some unpublished secondary data which is obtained from the rice mills of the public sector in Egypt from 2003 to 2014. The paper focuses on five main companies which are Domyat and Belqas, Dakahlia, Gharbia, Behiera and Kafer El-Sheikh. The most important results are that according to the dependent variable production (Y1), there is economic efficiency in rice mills Domyat and Belqas and Kafer El-Sheikh score by 1. While in rice mills Gharbia, Dakahlia and Behiera score by 40%, 49.3%, 38% (efficiency = 0.401, 0.507, and 0.622) respectively. While according to the dependent variable sales (Y2), there is economic efficiency in rice mills Domyat and Belqas, Gharbia, Dakahlia and Kafer El-Sheikh score by 1. While Behiera rice mills has economic inefficiency score by 21% (efficiency = 0.791)

The economic efficiency analysis of some rice mills in Egypt by using DEA and SFA

The main aim of this paper is measuring the economic efficiency of the rice mills public sector in Egypt and comparing the best company according to the economic efficiency. This aim is achieved by estimating the economic efficiency using Data Envelopment Analysis (DEA) and Stochastic Frontier Approach (SFA). This paper is based on some unpublished secondary data which is obtained from the rice mills of the public sector in Egypt from 2003 to 2014. The paper focuses on five main companies which are Domyat and Belqas, Dakahlia, Gharbia, Behiera and Kafer El-Sheikh. The most important results are that according to the dependent variable production (Y1), there is economic efficiency in rice mills Domyat and Belqas and Kafer El-Sheikh score by 1. While in rice mills Gharbia, Dakahlia and Behiera score by 40%, 49.3%, 38% (efficiency = 0.401, 0.507, and 0.622) respectively. While according to the dependent variable sales (Y2), there is economic efficiency in rice mills Domyat and Belqas, Gharbia, Dakahlia and Kafer El-Sheikh score by 1. While Behiera rice mills has economic inefficiency score by 21% (efficiency = 0.791)

ANTIBACTERIAL & ANTIFUNGAL POTENTIALITY OF RICINUS COMMUNIS & COLEUS FORSKOHLII ON SOME HUMAN PATHOGENIC MICROORGANISMS

The objective of the present study was to explore the antibacterial and antifungal activity of two plant extracts (Ricinus communis & Coleus forskohlii) against some selected pathogen (Staphylococcus aureus

RESPONSE OF RUTA GRAVEOLENS L. TO ROCK PHOSPHATE AND /OR FELDSPAR UNDER BIOLOGICAL FERTILIZERS

Two experiments were consummated at the Experimental Farm, National Research Center (NRC), Dokki, Cairo, Egypt during two succes-sive seasons of 2004/2005 and 2005/2006 to eval-uate the effect of natural products as a source of some important elements such as rock phosphate as a source of phosphorous and feldspar mica as a source of potassium with biological potassium phosphorous fertilizer or biological potassium fertilizer (Silicate bacterium) at different levels (0.0, 25, 50 and 100 g/L) on Ruta graveolens L. plant instead of the chemical fertilizes. Adding biological fertilizer with feldspar or rock phos-phate improved vegetative growth characters such as plant height (cm), branches number/ plant, fresh and dry weights of different plant parts i.e. leaves, stems and roots (g/plant), in addition to some chemical constituents as essential oil, total flavo-noides, P, K, Fe, Zn and Cu content. On the other hand, the main constituents of essential oil and N content were decreased compared with adding recommended chemical fertilizers

W

We investigate various classes of generalized closed fuzzy sets in [0,1]-topological spaces, namely, Wθg-closed fuzzy sets and Wδg-closed fuzzy sets. Also, we introduce a new separation axiom FT3/4∗ of the [0,1]-topological spaces, and we prove that every FT3/4∗-space is a FT3/4-space. Furthermore, we using the new generalized closed fuzzy sets to construct new types of fuzzy mappings

World Health Organization Surgical Safety Checklist with Addition of Infection Control Items: Intervention Study in Egypt

BACKGROUND: Surgical team is in command of the operating room (OR) and takes decisions regarding various patient care procedures. Educational programs directed to them, should be creative, provocative and tailored to their specific needs and the expected outcomes. AIM: This study aims to design and conduct an educational program of patient safety and infection control for the OR team based on the WHO surgical safety checklist and to assess their post-intervention knowledge and practices. METHODS: This interventional study was conducted at the ORs of Port-said general hospital. It passed through three stages; baseline assessment of knowledge and practice regarding patient safety and infection control among OR team (surgeons, anaesthetists and nurses), intervention stage in which an educational program based on the WHO surgical safety checklist with modifications and additions of more infection control items was conducted, then re-assessment of their post-intervention knowledge and practices. RESULTS: All the studied participants showed improvement in both knowledge and practices of patient safety and infection control after the educational program based on the WHO surgical safety checklist with modifications and additions of more infection control items and including not only practices but also knowledge as well, than before. CONCLUSION: The modification of the WHO surgical safety checklist to fit local knowledge and practices created a comprehensive tool that led to an improvement in both knowledge and practices of patient safety and infection control among the OR team

Expression of transient receptor potential vanilloid (TRPV) channels in different passages of articular chondrocytes

Ion channels play important roles in chondrocyte mechanotransduction. The transient receptor potential vanilloid (TRPV) subfamily of ion channels consists of six members. TRPV1-4 are temperature sensitive calcium-permeable, relatively non-selective cation channels whereas TRPV5 and TRPV6 show high selectivity for calcium over other cations. In this study we investigated the effect of time in culture and passage number on the expression of TRPV4, TRPV5 and TRPV6 in articular chondrocytes isolated from equine metacarpophalangeal joints. Polyclonal antibodies raised against TRPV4, TRPV5 and TRPV6 were used to compare the expression of these channels in lysates from first expansion chondrocytes (P0) and cells from passages 1–3 (P1, P2 and P3) by western blotting. TRPV4, TRPV5 and TRPV6 were expressed in all passages examined. Immunohistochemistry and immunofluorescence confirmed the presence of these channels in sections of formalin fixed articular cartilage and monolayer cultures of methanol fixed P2 chondrocytes. TRPV5 and TRPV6 were upregulated with time and passage in culture suggesting that a shift in the phenotype of the cells in monolayer culture alters the expression of these channels. In conclusion, several TRPV channels are likely to be involved in calcium signaling and homeostasis in chondrocytes