Functional Outcomes of Subaxial Spine Injuries Managed With 2-Level Anterior Cervical Corpectomy and Fusion: A Prospective Study

Vaibhav Jain,Ankit Madan,Manoj Thakur,Amit Thakur 대한척추신경외과학회 2018 Neurospine Vol.15 No.4

Objective: To evaluate the results of operative management of subaxial spine injuries managed with 2-level anterior cervical corpectomy and fusion with a cervical locking plate and autologous bone–filled titanium mesh cage. Methods: This study included 23 patients with a subaxial spine injury who matched the inclusion criteria, underwent 2-level anterior cervical corpectomy and fusion at our institution between 2013 and 2016, and were followed up for neurological recovery, axial pain, fusion, pseudarthrosis, and implant failure. Results: According to Allen and Ferguson classification, there were 9 cases of distractive extension; 4 of compressive extension; 3 each of compressive flexion, vertical compression, and distractive flexion; and 1 of lateral flexion. Sixteen patients had a score of 6 on the Subaxial Injury Classification system, and the rest had a score of more than 6. The mean follow-up period was 19 months (range, 12–48 months). Neurological recovery was observed in most of the patients (78.21%). All patients experienced relief of axial pain. None of the patients received a blood transfusion. Twenty-one patients (91.3%) showed solid fusion and 2 (8.69%) showed possible pseudarthrosis, with no complications related to the cage or plate. Conclusion: Two-level anterior cervical corpectomy and fusion, along with stabilization with a cervical locking plate and autologous bone graft-filled titanium mesh cage, can be considered a feasible and safe method for treating specific subaxial spine injuries, with the benefits of high primary stability, anatomical reduction, and direct decompression of the spinal cord.

Multi-Objective Optimization of Cascade Refrigeration System Using the Concept of Modified and Advanced Exergy, Risk Level and Thermal Inventory

Vaibhav Jain,Rajiv Rawat,Gulshan Sachdeva,Vikas Kumar 대한설비공학회 2020 International Journal of Air-Conditioning and Refr Vol.28 No.4

This work conceives the performance of vapor compression cascaded refrigeration system (CRS) from the exergy, safety and thermal inventory points of view employing the theory of effective temperature (T eff )Teff) than environment temperature (To) in Gouy–Stodola equation. Comparative results show that the actual irreversible loss in CRS is 8.1% higher. Further, advanced exergy analysis results showed that 17.985 kW irreversible loss (out of 33.737 kW irreversible loss) in the system is evadable with improvement in the system design. Besides, the vulnerability of toxic fluid R717 is reported in terms of the total risk level. Moreover, the economy matter is expressed in terms of its total thermal inventory. At the base case, total risk level and total thermal inventory are determined to be 454.3 US$ and 48.86 kW/K, respectively. First, sensitivity analysis is carried out to evaluate the variation in irreversible loss, total risk level and thermal inventory at different evaporator and condenser temperatures with different degrees of overlap (decision variables). A total of nine simulations are designed using the Taguchi technique. Later, multi-objective optimization is employed. The optimization process reduced the total irreversibility and annual risk level of CRS by 10.2% and 8.9%, respectively, with 6.8% increase in thermal inventory.

Robotic-assisted resection of proximal jejunal ischemic stricture and intracorporeal robot-sewn anastomosis

Vishu Jain,Peeyush Varshney,Subhash Chandra Soni,Vaibhav Kumar Varshney,B Selvakumar 대한내시경로봇외과학회 2022 Journal of Minimally Invasive Surgery Vol.25 No.4

With the advent of robotic surgery as an effective means of minimally invasive surgery in the last decade, more and more surgeries are being performed robotically in today’s world. Robotic surgery has several advantages over conventional laparoscopic surgery, such as three-dimensional vision with depth perception, magnified view, tremor filtration, and, more importantly, degrees of freedom of the articulating instruments. While the literature is abundant on robotic cholecystectomy and highly complex hepatobiliary surgeries, there is hardly any literature on robotic small bowel resection with intracorporeal anastomosis. We present a case of a 50-year-old male patient with a symptomatic proximal jejunal ischemic stricture who underwent robotic-assisted resection and robot-sewn intracorporeal anastomosis in two layers. He did well in the postoperative period and was discharged on postoperative day 4 with uneventful recovery. We hereby discuss the advantages and disadvantages of robotic surgery in such a scenario with a review of the literature.

Energy Analysis of a Vapor Compression System Cascaded with Ammonia-Water Absorption System

GULSHAN SACHDEVA,VAIBHAV JAIN,S. S. KACHHWAHA 대한설비공학회 2014 International Journal Of Air-Conditioning and Refr Vol.22 No.1

The first law analysis of a vapor compression–vapor absorption (VC–VA) cascade system iscarried out for a wide range of cooling capacity. While ammonia–water is the working pair in VAsection, R407C is used in VC section. The in°uences of change in cooling capacity, superheatingand subcooling in the condenser, temperature in the generator, degree of overlap in cascadecondenser, size of the heat exchangers etc. on the system performance are investigated. It isconcluded that the COP of the VC section of the cascade system could be improved by 146% andthe electricity consumption could be reduced by 64% compared to an equivalent VC unit. Separately the results showed the considerable increase in the generator heat when coolingcapacity was increased from 83.33kW. The COP of the cascade system at high cooling capacity isstrongly dependent on the performance of condenser.

EXERGY ANALYSIS OF A VAPOR COMPRESSION–VAPOR ABSORPTION CASCADE SYSTEM

GULSHAN SACHDEVA,VAIBHAV JAIN,S. S. KACHHWAHA 대한설비공학회 2013 International Journal of Air-Conditioning and Refr Vol.21 No.4

In this paper, second law analysis has been done for the vapor compression–vapor absorption (VC–VA) cascade system. Ammonia–water is considered as the working pair in absorption section and R407C is dealt as the working °uid in VC section. Exergy destruction or the irreversibility rate is determined in each components of VC–VA cascade system, for a wide range of cooling capacity by considering a variable speed reciprocating compressor. Further in this, Coe±cient of structural bond (CSB) analysis is carried out to quantify the effect of varying the generator temperature, effectiveness of solution heat exchanger, inlet temperature of external °uids in evaporator/condenser and some other variables. Solution heat exchanger and the condenser are reported to have high CSB value, so have a great scope of improvement to reduce the irreversibility rate of the whole system.

Performance analysis of a novel ejector-assisted condenser outlet split dual-evaporator refrigeration system

Sachdeva Gulshan,Anuradha Parinam,Jain Vaibhav,VenkataTeja Y. T. 대한설비공학회 2024 International Journal of Air-Conditioning and Refr Vol.32 No.1

The performance of an ejector-assisted condenser outlet split dual-evaporator cycle is compared with a conventional dual-evaporator cycle albeit consisting a pressure reducing valve. The cycles do not employ any separator due to its inability to efficiently separate the liquid and the vapor phases. The comparison of both the cycles has been made for the same cooling capacity in low-temperature evaporator and unit flow rate of R134a and R1234yf as refrigerants. The impacts of changing the operating temperatures of evaporator and condenser have been examined in the current investigation. The study reveals that with the increase in temperature of the high-temperature evaporator, the cooling capacity of the high-temperature evaporator yields, while that of the low-temperature evaporator plummets in both the cycles. Further, the compressor work is allayed in the ejector-assisted cycle; thus, the COP is enhanced considerably. The percentage COP improvement over the basic cycle is obtained from 14.7 to 17.53% for the refrigerant R1234yf and from 14.45 to 17.32% for R134a; however, the COP of both the cycles with R12134yf is slightly lower than with R134a. The ejector has been modeled assuming a constant pressure theory. The observed trend indicates that the entrainment ratio is improved with the rise in the temperature of low-temperature evaporator, whereas it is decreased with the rise in the temperature of high-temperature evaporator.

Morbidity Patterns among Menopausal Women in Rural Uttar Pradesh, India: A Cross-Sectional Study

( Debora J. Mathew ),( Sandip Kumar ),( Pankaj Kumar Jain ),( Dhiraj Kumar Srivastava ),( Vaibhav Singh ),( Kiran Krishnappa ) 대한폐경학회 2021 대한폐경학회지 Vol.27 No.1

Objectives: The quality of life declines gradually as women enter menopause, owing to the various problems associated with estrogen deficiency and aging, which adds to their morbidities. This study aimed to investigate the patterns of morbidity among rural menopausal women and compare the morbidity patterns among menopausal transition group and post-menopausal women. Methods: This community-based cross-sectional study included menopausal women aged 45-55 years from rural areas of the Etawah district, Uttar Pradesh, India. To select blocks and villages of the district, multistage random sampling was performed. According to a pretested, semistructured schedule, data were collected through interviews. Results: A total of 315 women participated in the study. The most frequent complaints among the participants were of feeling tired and worn out (85.1%) and of muscle and joint pains (67.6%). Poor memory (P = 0.046) and diabetes (P = 0.024) were more common in women who were in the menopause transition phase than in those who were in the postmenopausal phase. Conclusions: This study showed that majority of the menopausal women suffered from physical problems. Lifestyle modification and awareness programs will be beneficial among women in menopausal transition, to reduce the morbidity later in post-menopausal stage. Behaviour change communication, family and community support are essential in post-menopausal women, to help them cope with various morbid conditions.

Comparative performance investigation of a dual evaporator cycle using an ejector with the conventional cycle using a pressure reducing valve

Sachdeva Gulshan,Jaiswar Ajay,Anuradha Parinam,Jain Vaibhav 대한설비공학회 2023 International Journal of Air-Conditioning and Refr Vol.31 No.1

The performance of a dual evaporator cycle using ejector is compared with a conventional cycle employing pressure reducing valve. In both the systems, high temperature evaporator is considered as a flooded evaporator, thus a separator is employed after the high temperature evaporator. However, low temperature evaporator is a kind of conventional dry evaporator. The comparison of both systems, i.e., conventional and ejector assisted, is done for the same cooling capacities and same dryness fraction at the exit of high temperature evaporator with R134a, R152a, and R1234yf refrigerants. The effects of varying the states of refrigerant at the exit of flooded evaporator, and temperatures of both the evaporators and the condenser are analyzed using Engineering Equation Solver. It is found that the compressor work is reduced in both the cycles with the rise in low temperature evaporator temperature; however, a little variation is observed in the total cooling effect. The cooling effect in high temperature evaporator is increased with the increase in dryness fraction at the exit of the high temperature flooded evaporator, but it is decreased in low temperature evaporator.

An Experimental Investigation on Vapor Compression Refrigeration System Cascaded with Ejector Refrigeration System

Kumar Vikas,Sachdeva Gulshan,Tiwari Sandeep,Anuradha Parinam,Jain Vaibhav 대한설비공학회 2021 International Journal Of Air-Conditioning and Refr Vol.29 No.3

A conventional vapor compression refrigeration system (VCRS) cascaded with a heat-assisted ejector refrigeration system (ERS) has been experimentally analyzed. Cascading allows the VCRS to operate at lower condenser temperatures and thus achieve a higher coefficient of performance. In this cascaded system, the condenser of the vapor compression system does not dissipate its heat directly to the evaporator of the ERS; instead, water circulates between the condenser of VCRS and the evaporator of ERS to exchange the heat. Seven ejectors of different geometries have been used in the ERS; however, all the ejectors could not maintain thermal equilibrium at the desired operating conditions. The compressor of the cascaded VCRS consumed 1.3 times less power than the noncascaded VCRS. Furthermore, the cascaded system provided a maximum 87.74% improvement in COP over the noncascaded system for the same operating conditions. The performance of the system remained constant until the critical condenser pressure of the ERS.