Combined effect of relief and level of expansion in a suddenly expanded flow

This paper presents the experimental results on the flow characteristics of a suddenly expanded flow from the convergent nozzle for subsonic, sonic and sonic under expanded flow. In the present study micro jets were used to investigate the effect of micro jets on base pressure flow field in the enlarged duct. Accordingly an active control in the form of four micro jets of 1 mm orifice diameter located at 900 intervals along a pitch circle diameter of 1.3 times the nozzle exit diameter in the base region was employed. The NPRs of the present study are 1.5, 2.0, 2.5 and 3.0 and the area ratio (ratio of area of suddenly expanded duct to nozzle exit area) studied were 2.4, 3.61, 4.84, and 6.25. The length-to-diameter (i.e. L/D) ratio of the sudden expansion duct was varied from 10 to 1. From the results, it is seen that the flow in the base region is dominated by the waves, the general perception what we have that correctly expanded flow will be from waves is proved to be wrong; also, it is found that for L/D in the range L/D = 4, 3 and 2 the flow remains oscillatory mostly for NPRs 2.5 and 3.0. However, these oscillations are suppressed either with the increase in the L/D ratio in the range from 3 to 10 or with decrease in the level of expansion NPRs from 2.5 to 1.5. The present study explicitly reveals that, the base pressure in a suddenly expanded axi-symmetric duct can be controlled by employing micro jets under the influence of favorable pressure gradient

Simultaneous RP-HPLC determination of sparfloxacin and dexamethasone in pharmaceutical formulations

O presente estudo descreve o desenvolvimento e a subsequente validação de indicador de estabilidade simples e acurada por RP-HPLC para a determinação de esparfloxacino e dexametasona em formulações farmacêuticas na presença de produtos de degradação induzidos por estresse. Tanto os fármacos quanto os produtos de degradação induzidos pelo estresse foram separados em 10 minutos, utilizando coluna C8 e mistura de methanol e tampão fosfato 0,02 M, pH 3,0 (60:40 v/v, respectivamente) como fase móvel e detector de arranjo de diodo a 270 nm, A análise de regressão mostrou linearidade na faixa de 15-105 µg/mL para esparfloxacino e 5-35 µg/mL para a dexametsona. Todos os analitos foram resolvidos adequadamente com tailing aceitável. O pico de pureza dos dois foi maior que 0.9999, não mostrando picos de co-eluição. O método desenvolvido foi aplicado para a determinação simultânea de esparfloxacino e dexametasona em formulações farmacêuticas e para estudos de estabilidade.The present study describes the development and subsequent validation of simple and accurate stability indicating RP-HPLC method for the determination of sparfloxacin and dexamethasone in pharmaceutical formulations in the presence of their stress-induced degradation products. Both the drugs and their stress-induced degradation products were separated within 10 minutes using C8 column and mixture of methanol and 0.02 M phosphate buffer pH 3.0 (60:40 v/v, respectively) as mobile phase at 270 nm using diode array detector. Regression analysis showed linearity in the range of 15-105 µg/mL for sparfloxacin and 5-35 µg/mL for dexamethasone. All the analytes were adequately resolved with acceptable tailing. Peak purity of the two drugs was also greater than 0.9999, showing no co-elution peaks. The developed method was applied for simultaneous determination of sparfloxacin and dexamethasone in pharmaceutical formulations for stability studies

Development and analysis of tool wear and energy consumption maps for turning of titanium alloy (Ti6Al4V).

Machine tools are the main source of electric power consumption in industrial operations. Thus, in manufacturing, energy-efficient and cleaner production methods are preferred to mitigate production costs. Titanium alloys are known for their poor machinability and are generally characterized by low tool life, high energy consumption and poor surface quality due to its unique physical and mechanical properties. This research aims to evaluate the tool wear rate (R) and the specific cutting energy (SCE) at varying cutting conditions by developing tool wear and energy maps using unified cutting tests. Uncoated H13A tools were used during single-point turning of Ti-6Al-4V alloy by employing Full Factorial Design of Experiments. Based on experimental data, comprehensive process maps were developed for monitoring wear and energy data. These maps showed regions of (low moderate and high) wear and specific energy consumption. It was observed that while machining Ti-6Al-4V alloy the recommended cutting condition (V=100 m/min and f =0.16 mm/rev) enhances the tool life and reduces energy consumption together with high material removal rate. It was also deduced that instead of low speed, using a higher speed of 125 m/min will increase MRR by 127 % and SCE by 16 %, which is more feasible in a production environment. From tool-chip contact length and chip morphology analysis, a strong correlation indicated the reason behind the occurrence of various zones on the maps. It has been found that high wear and energy zone occurred due to the larger contact length and higher chip compression ratio when machining at high speed. The developed maps can be used to help the manufacturers achieve the economic and energy-efficient goal of machining

Stability indicating RP-HPLC method for simultaneous determination of gatifloxacin and dexamethasone in binary combination

In this study, conditions were optimized for development of a simple RP-HPLC method for simultaneous analysis of gatifloxacin and dexamethasone in different matrices like pharmaceuticals, human serum and urine. Good separation of gatifloxacin and dexamethasone from the induced degradation products was accomplished using C8 as stationary phase; 0.02 M phosphate buffer (pH 3.0) and methanol (42:58 v/v) as mobile phase. The concentration was measured with DAD at 270 nm. Linearity was observed in the range of 0.000040-0.000280 mol/L for gatifloxacin (r2≥0.999) and 0.000013-0.000091 mol/L for dexamethasone (r2≥0.999). Both the analyte peaks were completely separated from the peaks of induced degradation products as indicated by the peak purity index (≥0.9999 for both analytes). The optimized method is recommended to be used for concurrent analysis of gatifloxacin and dexamethasone in different matrices

RESEARCH DATA MANAGEMENT AND A SYSTEM DESIGN TO SEMI-AUTOMATICALLY COMPLETE INTEGRATED DATA MANAGEMENT PLANS [POSITION PAPER]

Data is an integral part of modern scientific work. Good research data management (RDM) and the communication of the related information is extremely an important matter. It is not only crucial for the ongoing research and its claims but also for the future uses of data. In recent years some guiding principles, e.g. FAIR principles and initiatives at the national and international level, e.g. NFDI, NFDI4Ing have also been founded to improve RDM. The data and its metadata are often handled in file system like structures which are versioned and logged. The information relating to the data handling are documented in data management plan (DMP). DMPs are also usually managed in similar file structures. These are made available in editable document formats as well as online free-text editable forms to which users are required to keep updating manually. These are isolated documents which have neither direct relation to data for verification nor are common to understand with consistency. In this paper, research data management of large-scale interdisciplinary projects is presented. On one hand it introduces, contemporary practices of RDM and on the other hand it helps researchers to determine the features of RDM system in the situations when it comes to select or develop a system for the same purpose. It further introduces a system design for semi-automatic completion of DMP functions in collaborative environment a.k.a. virtual research environment (VRE). It is assumed that the proposed system will assist and enable users to update semi-automatically integrated DMP during all phases of data life cycle. Direct relation to the data for verification, common understanding and consistency will also be maintainable

Active Control of Flow through the Nozzles at Sonic Mach Number

ABSTRACT The effectiveness of micro jets to control the base pressure in suddenly expanded axi-symmetric ducts are studied experimentally. As an active control in the form of four micro jets of 1 mm orifice diameter located at 90 0 intervals along a pitch circle diameter of 1.3 times the nozzle exit diameter in the base region was employed. The Mach number of the present study is unity. The area ratio (ratio of area of suddenly expanded duct to nozzle exit area) studied are 2.56, 3.24, 4.84 and 6.25. The L/D ratio of the sudden expansion duct varies from 10 to 1. From the experimental results, it is found that the micro jets can serve as active controllers for base pressure. Further, the control effectiveness of the micro jets is getting enhanced under the influence of favourable pressure gradient. To study the effect of micro jets on the quality of flow in the enlarged duct wall pressure was measured and it is found that the micro jets do not disturb the flow field

Simultaneous estimation of rosuvastatin and amlodipine in pharmaceutical formulations using stability indicating HPLC method

Utilizou-se abordagem de viabilidade custo-efetividade e isocrática, baseada em CLAE, empregando coluna C-18 (250 mm x 4,6 mm, 5 µm) para separar e avaliar os fármacos, rosuvastatina, anlodipino e seus produtos de degradação induzida por estresse, simultaneamente, em formulações farmacêuticas. Focada nos parâmetros das diretrizes da ICH, a separação eficiente de ambos os fármacos e de seus produtos de degradação foi obtida por meio da otimização da fase móvel com mistura de solventes 30:70 (v/v), respectivamente, acetonitrila e tampão acetato de amônio O,1 M (pH 5). A velocidade de fluxo da fase móvel foi de 1,5 mL/min e todas as detecções foram realizadas em 240 nm, utilizando detector de UV. O método foi linear no intervalo de concentração de 1-200 µg/mL para a rosuvastatina com coeficiente de determinação 0,996. Para o anlodipino, a linearidade ficou na faixa de 0.5-100 µg/mL, com coeficiente de determinação 0,994. Ambos os fármacos, junto com seus produtos de degradação, foram separados em menos de vinte minutos. Os resultados de precisão intra-dia e inter-dia variaram de 0,72 a 1,81% para a rosuvastatina e de 0,83 a 1,88%, para o anlodipino. Os resultados mostram que este método validado pelo ICH pode ser empregado com sucesso tanto para a rotina quanto para a quantificação simultânea da estabilidade de ambos os ingredientes ativos em formulações farmacêuticas.A viable cost-effective and isocratic approach employing C-18 column (250 mm × 4.6 mm, 5 µm) based HPLC has been utilized to separate and estimate the drugs, rosuvastatin, amlodipine and their stress induced degradation products, simultaneously in pharmaceutical formulations. Focused on ICH guideline parameters, the efficient separation of both drugs and their degradation products was achieved by optimizing a 30:70 (v/v) solvent mixture of acetonitrile and 0.1 M ammonium acetate buffer (pH 5) as mobile phase. The flow rate of the mobile phase was 1.5 mL/min and all the detections were carried out at 240 nm using UV detector. The method was linear in the concentration range of 1-200 µg/mL for rosuvastatin with 0.996 coefficient of determination value. For amlodipine, linearity was in the range of 0.5-100 µg/ml with 0.994 coefficient of determination value. Both the drugs along with their degradation products were separated in less than twenty minutes. The results of within-day and between-day precision were varied from 0.72 to 1.81% for rosuvastatin and 0.83 to 1.88% for amlodipine. The results show that this ICH validated method can be employed successfully for the routine as well as stability quantification of both the active ingredients simultaneously in pharmaceutical formulations

N-Acetyl-4-(benzene­sulfonamido)benzene­sulfonamide

In the mol­ecule of the title compound, C14H14N2O5S2, the dihedral angle between the aromatic rings is 77.75 (9)°. The acetamide group is planar [maximum deviation = 0.002 (3) Å] and oriented at dihedral angles of 13.49 (21) and 73.94 (10)° with respect to the aromatic rings. An intra­molecular C—H⋯O inter­action results in the formation of a six-membered ring. In the crystal structure, inter­molecular N—H⋯O and C—H⋯O inter­actions link the mol­ecules into a three-dimensional network, forming R 2 2(20) ring motifs

Exposure to Juvenile-Based Crime Reenactment Programs; A Study of Perceived Parental Stress

The current study aimed to examine relationship between juvenile based crime reenactment programs and the perceived parental stress related to it. Researchers hypothesized that there is an association between exposures to juvenile based crime reenactment programs and perceived parental stress. The sample comprised of 157 parents. A survey was conducted in Islamabad, based on purposive as well as convenient sampling. Data collection measures comprised demographic sheet, exposure to juvenile crime reenactment programs and Impact of Events Scale (IES). Factor Analysis was performed which constructed five factors i.e. effects on mental health; stress increase; effect on health; ability to handle situation and social Isolation. Moreover, Pearson Product-Moment Correlation test was performed to see the association between the exposures to juvenile based crime reenactment programs and perceived parental stress. A significant relationship was found between the juvenile crime base programs and perceived parental stress.&nbsp

Emerging Technologies for Connected and Smart Vehicles

[EN] The ten articles in this special section focus on new and emerging technologies for connected and smart vehicles. Due to the rapid growth of connected vehicles, many research constraints need to be addressed, e.g., reliability and latency, practical MAC and routing protocols, performance and adaptability to the changes in the environment (node density and oscillation in network topology), and validation of protocols under the umbrella of coherent assumptions using simulation methodologies. In this Feature Topic, we present 10 papers proposing very interesting solutions and architectures for futuristic and smarter connected vehiclesAhmed, SH.; Ben-Othman, J.; Lloret, J.; Khokhar, A.; Beyah, R.; Sánchez, A.; Guibene, W. (2018). Emerging Technologies for Connected and Smart Vehicles. IEEE Communications Magazine. 56(10):20-21. https://doi.org/10.1109/MCOM.2018.84931122021561