Vibration Control in MEMS Resonator Using Positive Position Feedback (PPF) Controller

In this paper, the vibration of a micro-electromechanical resonator with positive position feedback controller is studied. The analytical results are obtained to the first order approximation by using the multiple scale perturbation technique. The stability of the steady-state solution is presented and studied applying frequency response equations near the simultaneous primary and internal resonance cases. The effects of the controller and some system parameters on the vibrating system are studied numerically. The main result of this paper indicates that it is possible to reduce the vibration for the resonator system

Development of chitosan-glucose and chitosan-citric complexes edible coating to improve tomatoes post-harvest quality

 The effect of different shrimp chitosan molecular weights as well as shrimp chitosan complexes (chitosan-glucose and chitosan-citric) on the quality characteristics of the stored (at 7°C±2°C and 90% RH) tomato fruits (Lycopersicum esculentum) was investigated.  Coating tomatoes with high molecular weight chitosan (H.M.C.G) significantly improved firmness and weight loss.  The lowest weight loss was found in high molecular weight chitosan-glucose (H.M.C.G) treatment followed by the fruits coated with high molecular weight chitosan (HMC) and then uncoated tomato fruits.  Both molecular weights was clear on retarding the total acidity loss especially for stored tomato fruit coated with low molecular weight chitosan, while control tomatoes exhibited a larger reduction (p ≤ 0.05) in total acidity over storage.  Meanwhile, the increasing of cold storage time significantly (p ≥ 0.05) increased the pH in all uncoated and coated tomatoes.  Generally, no significant (P > 0.05) difference was observed in pH, titratable acidity and total soluble solids (T.S.S.) as well as sensory attributes among the tomato fruits coated with chitosan, chitosan citric and chitosan glucose.  Meanwhile, the fruits coated with low molecular weight chitosan had a higher (p ≥ 0.05) T.S.S. compared with that coated by the high molecular weight chitosan.   Keywords: chitosan, edible coating, tomatoes, firmness and weight loss

Molecular identification of Rosa x damascena growing in Taif region (Saudi Arabia)

A fragment of 772 bp of the chloroplast maturase K gene was amplified and sequenced for Rosa x damascena trigintipetala variety growing in Taif region of Saudi Arabia. The data were aligned with their counterparts of other varieties already found in the Genbank database and were analyzed by maximum-parsimony, neighbor-joining and maximum-likelihood methods and a single rooted tree was executed. R. x damascena trigintipetala was paraphyletic where one sample [A] clustered with all varieties while the second [B] was basal. R. x damascena was sister to R. x chinensis semperflorens with the later being basal. R. x damascena gori was basal for all taxa studied. R. moschata was inside the clade of R. x damascena. Hybridization could be possible among R. damascena, R. chinensis and R. moschata. The genetic distance and tree topology indicated that [A] variety could be originated from R. moshata while [B] could be originated from gori or R. chinensis semperflorens. We, therefore, may consider that R. x damascena gori or R. chinensis could be the origin of all nowadays R. x damascena varieties

n-Butyl 2-(2,4-dichloro­anilino)-4,4-dimethyl-6-oxocyclo­hex-1-enecarbo­dithio­ate

The cyclo­hexene ring in the title compound, C19H23Cl2NOS2, adopts an envelope conformation, with the C atom bearing the two methyl groups representing the flap. This atom deviates by 0.630 (2) Å from the plane passing through the other five atoms of the ring (r.m.s. deviation = 0.020 Å). The mol­ecular conformation is stabilized by an intra­molecular N—H⋯S hydrogen bond

Screw nail medialization of arytenoid in unilateral adductor vocal cord paralysis: A new office procedure

AbstractObjectivesThe aim of this study is to describe and evaluate new technique for treatment of unilateral vocal cord paralysis giving the same results of the standard procedure but minimizing the surgical trauma.Patients and methodsA prospective study was carried out between November 2009 and November 2011 in the Otorhinolaryngology Department, Zagazig University Hospitals, Egypt. It included 12 patients with unilateral idiopathic vocal cord paralysis who were managed by this new technique. Preoperative and postoperative video-laryngoscopy was done, maximal phonation time was calculated and ratings grade of dysphonia was compared.ResultsPostoperative video-laryngoscopy relieved complete glottic gap closure in 83.3% of cases and partial glottic gap in the remaining 16.7% of cases. The mean preoperative maximal phonation time was 9.42s and the postoperative value was 21.5s with a mean difference of 11.6s. The rating of the grade of dysphonia showed great improvement in the patient’s voice quality from severe dysphonia preoperatively to normal or near-normal voice postoperatively. All patients were satisfied with the results of the procedure except one patient (8.3%).ConclusionThe screw nail medialization technique gives a good reliable and easy procedure under local anesthesia for managing unilateral vocal cord paralysis and avoids the disadvantages of infection laryngoplasty and medialization thyroplasty using implants

Mitigation Voltage Sag Using DVR with Power Distribution Networks for Enhancing the Power System Quality

The fast developments in power electronic technology have made it possible to mitigate voltage disturbances in power system. Among the voltage disturbances challenging the industry, the voltage sags are considered the most important problem to the sensitive loads. The Dynamic Voltage Restorer (DVR) is mainly used in a utility grid to protect the sensitive loads from power quality problems, such as voltage sags and swells. However, the effectiveness of the DVR can wane under unbalanced grid voltage conditions. DVR is recognized to be the best effective solution to overcome this problem. The primary advantage of the DVR is keeping the users always on-line with high quality constant voltage maintaining the continuity of production. In this paper, the usefulness of including DVR in distribution system for the purpose of voltage sag and swell mitigation is described. This paper describes the DVR operation strategies and control. The DVR operation with the distribution networks is found very efficient for detecting and clearing any power quality disturbance in distribution systems. Results of simulation using MATLAB/Simulink are demonstrated to prove the usefulness of this DVR design and operation to enhance the power system quality

UTJECAJ FILTRIRANJA I CENTRIFUGIRANJA RAZRJEĐIVAČA SPERME NA VIJABILNOST OHLAĐENE SPERME BIKA BUFALA

This study was conducted to investigate influence of filtration or centrifugation of TRIS milk diluent on the viability and acrosomal integrity of buffalo spermatozoa preserved under refrigeration condition. Semen ejaculates (n=40) were collected twice weekly using artificial vagina. Each ejaculate was exposed to the following diluents, TRIS (T1 to T4), Milk (M1 to M8), and combinations of TRIS and milk diluents at different ratios (TM1 to TM11). Some parameters as live percentage, viability indicies and acrosomal integrity of spermatozoa was calculated immediately following dilution of semen, then at 3rd, 6th and 9th day of storage at refrigeration temperature (5ºC). Data were statistically analyzed. The results revealed that centrifugation of TRIS diluent once (T3) or twice (T4), before dilution processes, had a beneficial effect on the examined parameters of diluted semen (live percentage, viability indicies and acrosomal integrity of spermatozoa) during the entire period of storage when compared with control TRIS diluent (T1) or filtrated TRIS diluent (T2). However, T3 was the best of all (T1, T2 or T4). Centrifugation of milk-yolk diluent (M3) was found better than any other treatment for the examined milk diluents. Moreover, M3 was the best of all followed by M4 and M6, then followed by the others. Likewise, a combination of T3 and M3 at a ratio of 50:50 (TM6) was, in many aspects, superior to any other combination (TM1 to TM11) or diluents used in this study for dilution and preservation of buffalo semen at refrigeration temperature. It can be concluded that centrifugation of TRIS or milk diluent once before dilution would be the best treatment. Moreover, combination of one part of centrifuged TRIS diluent and one part of centrifuged milk diluents proved to be the proper diluent of choice for dilution and preservation of buffalo semen. It is recommended to use this combination to dilute and freeze buffalo semen for the artificial insemination program.Cilj ovoga rada bio je istražiti utjecaj filtriranja i centrifugiranja razrjeđivača TRIS i mliječnog razrjeđivača na vijabilnost i akrosomalni integritet sperme bufala čuvane u uvjetima hlađenja. Ejakulati sperme (n=40) sakupljani su dvaput tjedno primjenom umjetne vagine. Svaki ejakulat izložen je sljedećim razrjeđivačima: TRIS (T1 do T4), mlijeko (M1 do M8) i kombinacija razrjeđivača TRIS i mliječnog razrjeđivača (TM1 do TM11). Neki su parametri, kao živi postotak, vijabilnost i akrosomalni integritet sperme, izračunati odmah nakon rezrjeđivanja sperme, zatim 3., 6. i 9. dan čuvanja na temperaturi hlađenja (5°C). Podaci su statistički analizirani. Rezultati su pokazali da centrifugiranje razrjeđivačem TRIS jedanput (T3) ili dvaput (T4) prije procesa razrjeđivanja ima povoljan utjecaj na ispitivane parametre razrjeđivanja sperme (živi postotak, vijabilnost i akrosomalni integritet sperme) u cijelom razdoblju čuvanja, u usporedbi s kontrolnim razrjeđivačem TRIS (T1) ili filtriranim razrjeđivačem (T2). Međutim, T3 je bio najbolji od svih (T1, T2 ili T4). Centrifugiranje razrjeđivača mlijeko-žumanjak (M3) pokazalo se boljim od bilo kojeg tretiranja ispitivanih mliječnih razrjeđivača. Štoviše, M3 je bio najbolji, slijede M4 i M6, a zatim ostali. Isto tako, kombinacija T3 i M3 u omjeru 50:50 (TM6) bila je u mnogo pogleda bolja od bilo koje druge kombinacije (TM1 do TM11) razrjeđivača upotrijebljenih u ovom istraživanju. Može se zaključiti da bi centrifugiranje TRIS ili mliječnim razrjeđivačem jedanput prije razrjeđivanja bio najbolji tretman za očuvanje sperme bufala na temperaturi hlađenja. Osim toga, kombinacija jednog dijela centrifugiranog razrjeđivača TRIS i jednog dijela centrifugiranih mliječnih razrjeđivača pokazala se pravim izborom za razrjeđivanje i očuvanje sperme bufala. Preporuča se upotreba ove kombinacije za razrjeđivanje i zamrzavanje sperme bufala za program umjetne oplodnje

Intelligent Dynamic Backlash Agent: A Trading Strategy Based on the Directional Change Framework

The Directional Changes (DC) framework is an approach to summarize price movement in financial time series. Some studies have tried to develop trading strategies based on the DC framework. Dynamic Backlash Agent (DBA) is a trading strategy that has been developed based on the DC framework. Despite the promising results of DBA, DBA employed neither an order size management nor risk management components. In this paper, we present an improved version of DBA named Intelligent DBA (IDBA). IDBA overcomes the weaknesses of DBA as it embraces an original order size management and risk management modules. We examine the performance of IDBA in the forex market. The results suggest that IDBA can provide significantly greater returns than DBA. The results also show that the IDBA outperforms another DC-based trading strategy and that it can generate annualized returns of about 30% after deducting the bid and ask spread (but not the transaction costs

The Influence of Urbanization on Natural Overland Flow Paths

This paper studies the influence of urbanization on the natural overland flow paths on topography. The main objectives of this study are to: measure the effectiveness of drainage networks, study the influences of urban structure, compare the pre-and post-urban overland flow paths, and provide recommendations for flood prevention. The study was conducted on a catchment (81 km2) in Qatar that lies between Doha and Al-Rayan. Land cover, soil data, rain data, and digital elevation model (DEM) were the main inputs of the study to obtain run-off depths, time of concentration, and peak flows. The Soil Conservation Service (SCS) method was applied, where Curve Numbers (CNs) were identified for each land cover based on soil groups concerning the infiltration rate. A geographic information system (GIS) integration has provided better results. ArcMap tools have been used to study flow changes such as flow direction, flow accumulation, and stream definition. The result of the study shows that urbanization has a significant effect on the characteristics of the flow path as it causes the time of concentration to decrease, resulting in increased run-off depth and peak flow

2-Hydroxy­ethyl 2-(2,4-dichloro­anilino)-4,4-dimethyl-6-oxocyclo­hex-1-ene­carbo­dithio­ate

The six-membered cyclo­hexene ring in the title compound, C17H19Cl2NOS2, adopts an envelope conformation, with the C atom bearing the two methyl groups representing the flap. This atom deviates by 0.716 (3) Å from the plane passing through the other five atoms of the ring (r.m.s. deviation = 0.072 Å). The mol­ecular conformation is stabilized by an intra­molecular N—H⋯S hydrogen bond. The hydr­oxy group engages in inter­molecular O—H⋯O hydrogen bonding with adjacent acceptor atoms to generate a zigzag chain running along the c axis