Performance Enhancements in LiCl-H2O and LiBr-H2O Absorption Cooling Systems through an Advanced Exergetic Analysis

Parth Mody,Jatin Patel,Nishant Modi,Bhargav Pandya 대한설비공학회 2021 International Journal of Air-Conditioning and Refr Vol.29 No.1

This research study compares the thermodynamic performance of 10 kW lithium chloride–water (LiCl–H2O) and lithium bromide–water (LiBr–H2O) absorption cooling systems through first and second law of thermodynamics. Further, the exergy degradations happening in each component have been split into unavoidable and avoidable exergy degradations as well as endogenous and exogenous exergy degradations through advanced exergy analysis. Pressure–temperature–concentration (P–T –X) diagrams are drafted to clarify the real, ideal, and unavoidable cycles for LiCl–H2O and LiBr–H2O absorption cycles. Moreover, this paper exhibits the sensitivity of various system components towards the generator, condenser, and absorber temperature for both pairs. Energetic observation proves that LiCl–H2O pair is 10% more efficient as compared to LiBr–H2O pair. Exergetically, LiBr–H2O cycle struggles with additional (nearly 13.45%) exergy destruction than LiCl–H2O cycle. The major contribution (around 70% to 80%) of irreversibility comes from the generator and absorber. Comprehensively, the parametric partitions of irreversibility rate in each component provide broad indications to prioritize the system components for enhancements.

Lumbar Nerve Root Occupancy in the Foramen in Achondroplasia : A Morphometric Analysis

Modi, Hitesh N.,Suh, Seung Woo,Song, Hae-Ryong,Yang, Jae Hyuk Ovid Technologies (Wolters Kluwer) - Lippincott Wi 2008 Clinical orthopaedics and related research Vol.466 No.4

Accuracy of thoracic pedicle screw placement in scoliosis using the ideal pedicle entry point during the freehand technique

Modi, Hitesh,Suh, Seung Woo,Song, Hae-Ryong,Yang, Jae-Hyuk Springer-Verlag 2009 International orthopaedics Vol.33 No.2

Surgical Correction and Fusion Using Posterior-Only Pedicle Screw Construct for Neuropathic Scoliosis in Patients With Cerebral Palsy: A Three-Year Follow-up Study

Modi, Hitesh N.,Hong, Jae-Young,Mehta, Satyen S.,Srinivasalu, S,Suh, Seung-Woo,Yi, Ju-Won,Yang, Jae-Hyuk,Song, Hae-Ryong Lippincott Williams Wilkins, Inc. 2009 1528-1159) Vol.34 No.11

STUDY DESIGN.: It is a retrospective study of 52 neuromuscular scoliosis patients with cerebral palsy (CP). OBJECTIVE.: To determine the effectiveness and amount of correction using posterior-only pedicle screw construct. SUMMARY OF BACKGROUND DATA.: Although there have been many reports in literature supporting the use of pedicle screw-only constructs for the correction of adolescent idiopathic scoliosis, similar studies have not been reported in patients with CP. METHODS.: We retrospectively evaluated outcomes of 52 neuropathic scoliosis patients (28 males and 24 females) with CP over minimum 2 years of follow-up. All patients underwent pedicle screw fixation without any anterior procedure for the correction. Pelvic fixation was done in 10 patients who had pelvis obliquity more than 15°. All coronal and sagittal parameters were noted after surgery and at final follow-up. Patient’s functional outcome was measured using modified Rancho Los Amigos Hospital system criteria. Complications were recorded from record sheets and any change in the ambulatory status was also recorded. RESULTS.: Mean age was 22 years at the time of operation and average follow-up was 36.1 month. Cobb’s angle was improved to 62.9% (P < 0.0001) from 76.8° to 30.1° after surgery and 31.5° at final follow-up. This correction of scoliosis (41%∼92%) was found to be statistically significant (P < 0.0001). Overall correction in pelvic obliquity was 56.2% from 9.2° before surgery to 4.0° after surgery which was 43.1% at final follow-up to 5.2°. Twenty-one patients (42%) improved their functional ability by grade 1 with 2 patients by grade 2. After the operation parent or caretakers of patients exhibited better sitting balance and nursing care. There were 32% complications in the series major being pulmonary. There were 2 perioperative deaths and 1 patient developed neurologic deficit due to screw impingement in canal, which was resolved after removal. CONCLUSION.: We reported satisfactory coronal and sagittal correction with posterior-only pedicle screw fixation without higher complication rate in CP patients. Further long-term study is recommended to evaluate the success of pedicle screw in this population.

Drooping of Apical Convex Rib-vertebral Angle in Adolescent Idiopathic Scoliosis of More Than 40 Degrees: A Prognostic Factor for Progression

Modi, Hitesh N.,Suh, Seung Woo,Song, Hae-Ryong,Yang, Jae-Hyuk,Ting, Chen,Hazra, Sunit Lippincott Williams Wilkins, Inc. 2009 Journal of spinal disorders & techniques Vol.22 No.5

STUDY DESIGN: It is a retrospective analysis on radiograms of 113 adolescent idiopathic scoliosis (AIS) patients with a curve of 40 degrees or more at the time of presentation. OBJECTIVES: Our aim was to find out the prognostic factor for the curve progression for this group. SUMMARY AND BACKGROUND: There is general consensus in favor of operation when the curve is more than 40 degrees for AIS. There are number of reports on the prognostic and etiologic factors for the progression of scoliosis. Rib-vertebral angle (RVA) became a topic of interest regarding the progression of scoliosis for many researchers since Mehta introduced it in 1972. METHODS: There were 113 AIS patients (95 females and 18 males) who had a curve of more than 40 degrees at the time of presentation, with an average age of 12 years and 10 months. We measured RVA on the convex and concave sides at the apex and 12th vertebrae and measured rib-vertebral angle difference (RVAD) using Mehta’s method at each follow-up. We also measured the drooping value of the convex rib after bracing and at final follow-up. RESULTS: Of the 113 patients, 84 responded to bracing and in 29 the curve progressed despite bracing at final follow-up. The average drooping of rib at the apex on the convex side was 11 degrees, which progressed compared with 0.12 degrees in those who responded to treatment. On analyzing the results we could not find any relationship in 12th vertebrae but there was a significant relationship between the drooping value of convex apical rib (RVA Cx) after bracing and curve progression, which is similar to RVAD. There was no relationship between curve progression and initial angle, age, Risser sign, or menarchal status at presentation. CONCLUSIONS: From our study, we conclude that a large number of curves can be treated with bracing; however, when we notice drooping of the convex apical rib along with RVAD, the curve will likely progress.

A practical approach for kinetic analysis of hydrogenation of complex mineral base oil

Modi Siddharth,Tiwari Anand Kumar,Rao Meka Srinivasa,Snigdha Thummalapalli,Saritha Thummalapalli,Gupta Thummalapalli Chandra Sekhara Manik,Kumar Ajay 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.7

The mineral base oil contains paraffins, naphthenes and aromatic hydrocarbons (AH) with carbon chains ranging from C14 to C60. The presence of AH in base oil affects the performance of the product in many industrially oriented applications. The base oil considered in this work had AH around 14% w/w that needed to be reduced below 5% w/w for some applications and ideally 0% w/w. This paper demonstrates the practical approach for hydrogenation of complex mineral base oil for reducing AH. The mineral base oil rich in C20 was taken as the representative component. The hydrogen solubility in the oil was estimated using NRTL model. The semi-batch hydrogenation experiments were performed at different conditions and conversion of AH as high as 79% (i.e. 3% w/w) could be achieved. A second-order pseudo-homogeneous reaction kinetic model was proposed and validated. The conditions for reaction kinetics were optimized to achieve desirable conversion using Aspen Plus. To develop a continuous process for hydrogenation of AH, experiments were performed in a lab scale fixed bed reactor and the applicability of the kinetic model was validated. The kinetics was observed to be free of internal and external mass transfer limitations under lab scale conditions.

Part-of-speech Tagging for Hindi Corpus in Poor Resource Scenario

Modi, Deepa,Nain, Neeta,Nehra, Maninder Korea Multimedia Society 2018 The journal of multimedia information system Vol.5 No.3

Natural language processing (NLP) is an emerging research area in which we study how machines can be used to perceive and alter the text written in natural languages. We can perform different tasks on natural languages by analyzing them through various annotational tasks like parsing, chunking, part-of-speech tagging and lexical analysis etc. These annotational tasks depend on morphological structure of a particular natural language. The focus of this work is part-of-speech tagging (POS tagging) on Hindi language. Part-of-speech tagging also known as grammatical tagging is a process of assigning different grammatical categories to each word of a given text. These grammatical categories can be noun, verb, time, date, number etc. Hindi is the most widely used and official language of India. It is also among the top five most spoken languages of the world. For English and other languages, a diverse range of POS taggers are available, but these POS taggers can not be applied on the Hindi language as Hindi is one of the most morphologically rich language. Furthermore there is a significant difference between the morphological structures of these languages. Thus in this work, a POS tagger system is presented for the Hindi language. For Hindi POS tagging a hybrid approach is presented in this paper which combines "Probability-based and Rule-based" approaches. For known word tagging a Unigram model of probability class is used, whereas for tagging unknown words various lexical and contextual features are used. Various finite state machine automata are constructed for demonstrating different rules and then regular expressions are used to implement these rules. A tagset is also prepared for this task, which contains 29 standard part-of-speech tags. The tagset also includes two unique tags, i.e., date tag and time tag. These date and time tags support all possible formats. Regular expressions are used to implement all pattern based tags like time, date, number and special symbols. The aim of the presented approach is to increase the correctness of an automatic Hindi POS tagging while bounding the requirement of a large human-made corpus. This hybrid approach uses a probability-based model to increase automatic tagging and a rule-based model to bound the requirement of an already trained corpus. This approach is based on very small labeled training set (around 9,000 words) and yields 96.54% of best precision and 95.08% of average precision. The approach also yields best accuracy of 91.39% and an average accuracy of 88.15%.

Observer reliability between juvenile and adolescent idiopathic scoliosis in measurement of stable Cobb’s angle

Modi, Hitesh N.,Chen, Ting,Suh, Seung Woo,Mehta, Satyen,Srinivasalu, S.,Yang, Jae-Hyuk,Song, Hae-Ryong Springer-Verlag 2009 European spine journal Vol.18 No.1

Thermodynamic and Economic Contrast of an Ionic Solution Operated Solar Absorption Cooling System with LiBr + H_2O Pair for a Business Building in India

Nishant Modi,Bhargav Pandya,Jovad Hosseinpour,Majid Amidpour 대한설비공학회 2019 International Journal of Air-Conditioning and Refr Vol.27 No.4

The current study assesses the thermo-economic performance of a H2O+[EMIM][DMP] (1-ethyl-3-methylimidazolium dimethyl phosphate) working fluid-based absorption machine coupled with various solar collectors to cater the cooling load to business building at Gandhinagar city, India. H2O+[EMIM][DMP] could be an alternative to conventional LiBr+ H2O working fluid pair of absorption machines as it can operate without problem of crystallization which is perquisite for the continuous operation of the system. A mathematical model is developed to simulate the proposed system with 10kW cooling capacity at 5∘C. The sensitivity assessment is carried out to find the effect of various parameters including heat source temperature on the coefficient of performance (COP) and exergetic efficiency for each collector case. The optimum SCOP of parabolic trough collector (PTC)-based system is 11.43% higher compared to ETC-based system, whereas the ETC-based system is 25.10% economical than the PTC-based system. Furthermore, payback period for ETC-based system is only one month higher than FPC-based system, which altogether exhibits the superiority of ETC-coupled H2O+[EMIM][DMP] absorption refrigeration system over FPC-based system.

Purification and Characterization of κ-Carrageenase from a Novel γ-Proteobacterium, Pseudomonas elongata(MTCC 5261) syn. Microbulbifer elongatuscomb. Nov

Kalpana Mody,Yasmin Khambhaty,B. Jha 한국생물공학회 2007 Biotechnology and Bioprocess Engineering Vol.12 No.6

The phenotypic and carrageenolytic features of a novel halo tolerant marine bacterium, isolated from decayed red algal samples collected along the west coast of India were studied. This gram-negative strain was identified as Pseudomonas elongata (MTCC 5261) syn. Microbulbifer elongatus comb. nov according to its morphological, physiological and molecular characterization. The extracellular κ-carrageenase was purified 106.54-fold by a combination of ammonium sulfate precipitation (40~60%) and successive gel filtration chromatography. The purified protein fraction yielded significantly high activity of 426.19 units/mg protein and migrated as a single band on a sodium dodecyl sulfate polyacrylamide gel electrophoresis with a molecular weight of ~128 kDa. For κ-carrageenase activity, optimum temperature was 40℃ whereas two pH optima i.e. 5.6 and 7.7 were observed. For κ-carrageenan, the enzyme gave a Km value of 6.66 mg/mL and a Vmax value of 4 μmol/min/mg when the reaction was carried out at 40℃ and pH 5.6. Isolated κ-carrageenase could successfully generate protoplasts of Kappaphycus alvarezii. This is the first report on the production of κ-carrageenase by this bacterium isolated from west coast of India. Molecular mass and various characteristics showed that the carrageenase from P. elongata was much different from those previously reported.