Two fast-growing Indian species, Melia composita Benth. and Eucalyptus tereticornis Sm., which have different sets of physical properties, were dried together in a vacuum press dryer(VPD) under two drying conditions,i...Two fast-growing Indian species, Melia composita Benth. and Eucalyptus tereticornis Sm., which have different sets of physical properties, were dried together in a vacuum press dryer(VPD) under two drying conditions,i.e., above boiling point(ABP) and below boiling point(BBP). The ABP and BBP conditions were maintained by keeping the temperature constant at 75 ℃ and maintaining two pressure levels: 300 mm of Hg(ABP) and 450 mm of Hg(BBP). In order to understand pressure conditions at the core during vacuum drying, a cylindrical brass pipe was inserted in both wood cores and attached with pressure gauges placed outside of the VPD. The results indicate that the Melia wood core attained equilibrium pressure immediately with the pressure of VPD, while Eucalyptus attained it very slowly, reaching equilibrium at later stages of drying when cracks and checks advanced to the core.The drying rate was higher for Melia than Eucalyptus under both drying conditions. The drying rate of Melia(ABP) was higher than Melia(BBP), however, the drying rate for Eucalyptus(ABP) was not significantly different from the BBP drying rate.展开更多
Plantation-grown progenies of Melia composita Willd.were studied for variability in several physical properties： density,radial and tangential shrinkage,longitudinal permeability of heartwood and sapwood.Furthermore,...Plantation-grown progenies of Melia composita Willd.were studied for variability in several physical properties： density,radial and tangential shrinkage,longitudinal permeability of heartwood and sapwood.Furthermore,flat-sawn planks from each of the progeny were subjected to a quick-drying test for determination of kilndrying schedule.The mean density of the species was 0.39 g cm^（-3） and the wood may be categorized as light wood.Mean radial shrinkage（%） for the species was 2.8% with progeny-wise variation in radial shrinkage from 1.56 to 4.11%.Mean tangential shrinkage（%） for the species was 5.54% with progeny-wise variation in tangential shrinkage from 3.69 to 7.71%.The resultant tangentialradial shrinkage ratio was 1.98（less than two）,which suggests that the wood is relatively stable with respect to drying behavior.Mean sapwood and heartwood longitudinal permeability of the species were 3.38 and 2.02 Darcy,respectively.Higher longitudinal permeability of sapwood and heartwood indicate better drying and preservative properties of the species.Terazawa quick-drying test method suggests that the species is less susceptible to drying defects.During the test,only moderate checks and cracks were observed.A tentative kiln-drying schedule was recommended based on these results.展开更多
Cemento-ossifying fibroma (COF) of maxilla is comparatively rare lesion of the maxillofacial region. There is often a misdiagnosis in the category of fibroosseous lesions, owing to an overlap of clinical, histological...Cemento-ossifying fibroma (COF) of maxilla is comparatively rare lesion of the maxillofacial region. There is often a misdiagnosis in the category of fibroosseous lesions, owing to an overlap of clinical, histological and radiographic features amongst the separate entities. We present a case of giant maxillary COF causing extensive disfiguration of the face, along with extensive review of the clinico-pathologic and treatment aspects of the fibro-osseous lesions.展开更多
BACKGROUND The exponential rise in Coronavirus disease 2019(COVID-19)cases has resulted in an increased number of patients requiring prolonged ventilatory support and subsequent tracheostomy.With the limited availabil...BACKGROUND The exponential rise in Coronavirus disease 2019(COVID-19)cases has resulted in an increased number of patients requiring prolonged ventilatory support and subsequent tracheostomy.With the limited availability of literature regarding the outcomes of COVID-19 patients with tracheostomy,we attempted to study the clinical characteristics and multiple parameters affecting the outcomes in these patients.AIM To determine all-cause mortality following tracheostomy and its association with various risk factors in COVID-19 patients.METHODS This retrospective study included 73 adult COVID-19 patients admitted to the ICU between 1 April,2020 and 30 September,2021 who underwent tracheostomy as a result of acute respiratory failure due to COVID-19.The data collected included demographics(age,sex),comorbidities,type of oxygen support at admission,severity of COVID-19,complications,and other parameters such as admission to tracheostomy,intubation to tracheostomy,ICU stay,hospital stay,and outcome.RESULTS This study included 73 adult patients with an average age of 52±16.67 years,of which 52%were men.The average time for admission to tracheostomy was 18.12±12.98 days while intubation to tracheostomy was 11.97±9 days.The mortality rate was 71.2%and 28.8%of patients were discharged alive.The mean duration of ICU and hospital stay was 25±11 days and 28.21±11.60 days,respectively.Greater age,severe COVID-19,mechanical ventilation,shock and acute kidney injury were associated with poor prognosis;however,early tracheostomy in intubated patients resulted in better outcomes.CONCLUSION Patients with severe COVID-19 requiring mechanical ventilation have a poor prognosis but patients with early tracheostomy may benefit with no added risk.We recommend that the timing of tracheostomy be decided on a case-by-case basis and a well-designed randomised controlled trial should be performed to elucidate the potential benefit of early tracheostomy in such patients.展开更多
Electric vehicles(EVs)are one of the more emerging and significant areas,representing the future of transportation.Moreover,the increased demand for EVs brings greater attention toward the development of the charging ...Electric vehicles(EVs)are one of the more emerging and significant areas,representing the future of transportation.Moreover,the increased demand for EVs brings greater attention toward the development of the charging infrastructure.Therefore,this paper addresses the multifunctional charging system integrated with the grid,EV battery and household utilities.It presents an improved idea about the charging system with grid connection and its connection to the varying local nonlinear load.It consists of a voltage source converter(VSC)tied to the grid and bidirectional converter,which charges/discharges the battery and also regulates the constant voltage across the DC bus,where all the vehicles are connected for charging.It also shows the operations of charging/discharging the battery of EVs and the voltage and current profile across the battery as per the state of charge(SOC)limits.Moreover,the sparse constrained proportionate normalized least mean fourth(SCP-NLMF)based method is used to control the charging system by estimating the active component of load current.The derived mean square error(MSE)of load current is improved due to low convergence rates in later periods.The adaptation process becomes more accurate by mitigating the MSE error of load current to converge faster and the dynamic response is further improved.The simulated and tested results validate the accuracy and efficacy of the SCPNLMF technique and charging system.展开更多
In this work,we present a photovoltaic(PV)-based off-board charging system integrated with the grid using a voltage source converter(VSC).The control of the grid-tied off-board charger is derived from the joint logari...In this work,we present a photovoltaic(PV)-based off-board charging system integrated with the grid using a voltage source converter(VSC).The control of the grid-tied off-board charger is derived from the joint logarithmic hyperbolic cosine robust sparse adaptive filter(JLHCAF)algorithm.This algorithm effectively tracks the fundamental component of the load current in a short duration,providing a good dynamic response.Due to its robustness against impulsive interference,the JLHCAF outperforms other sparsity-aware robust algorithms The cascaded proportional-integral(PI)controller is used to control the bidirectional buck-boost converter for electric vehicle(EV)charging/discharging,which acts in buck operation if the EV is being charged and in boost operation if it is discharged.The reference DC link voltage for the controller is derived by using adaptive MPPT technique.The bidirectional properties of the system enable various functions,including grid-to-vehicle(G2V),vehicle-to-grid(V2G),PV source-to-grid(PV2G),vehicle-to-home(V2H),and PV source-to-vehicle(PV2V)operations.Additionally,the system can supply power to critical nonlinear loads.The control strategy ensures compliance with the power quality requirements set by the IEEE standard,as demonstrated in the results.To validate the effectiveness of the proposed system,we conducted tests under dynamic conditions by disconnecting and reconnecting household loads.Furthermore,the off-board charging system was subjected to actual conditions,such as variations in solar PV insolation,and its steady-state performance was evaluated through simulation and laboratory experimental prototypes.The results,including total harmonic distortion(THD),support the validation of the developed charging system.展开更多
The physio-chemical changes in concrete mixes due to different coarse aggregate(natural coarse aggregate and recycled coarse aggregate(RCA))and mix design methods(conventional method and Particle Packing Method(PPM))a...The physio-chemical changes in concrete mixes due to different coarse aggregate(natural coarse aggregate and recycled coarse aggregate(RCA))and mix design methods(conventional method and Particle Packing Method(PPM))are studied using thermogravimetric analysis of the bydrated cement paste.A method is proposed to estimate the degree of hydration(a)from chemically bound water(WB).The PPM mix designed concrete mixes exhibit lower a.Recycled aggregate concrete(RAC)mixes exhibit higher and a after 7 d of curing,contrary to that after 28 and 90 d.The chemically bound water at infinite time(WBo)of RAC mixes are lower than the respective conventional concrete mixes.The lower WBo,Ca(OH)2 bound water,free Ca(OH)2 content and FT-IR analysis substantiate the use of pozzolanic cement in the parent concrete of RCA.The compressive strength of concrete and a cannot be correlated for concrete mixes with different aggregate type and mix design method as the present study confirms that the degree of hydration is not the only parameter which governs the macro-mechanical properties of concrete.In this regard,further study on the influence of interfacial transition zone,voids content and aggregate quality on macro-mechanical properties of concrete is needed.展开更多
基金part of M.Sc.dissertation under financial support from ‘‘Forest Research Institute(Deemed)University,Dehradun(India)’’
文摘Two fast-growing Indian species, Melia composita Benth. and Eucalyptus tereticornis Sm., which have different sets of physical properties, were dried together in a vacuum press dryer(VPD) under two drying conditions,i.e., above boiling point(ABP) and below boiling point(BBP). The ABP and BBP conditions were maintained by keeping the temperature constant at 75 ℃ and maintaining two pressure levels: 300 mm of Hg(ABP) and 450 mm of Hg(BBP). In order to understand pressure conditions at the core during vacuum drying, a cylindrical brass pipe was inserted in both wood cores and attached with pressure gauges placed outside of the VPD. The results indicate that the Melia wood core attained equilibrium pressure immediately with the pressure of VPD, while Eucalyptus attained it very slowly, reaching equilibrium at later stages of drying when cracks and checks advanced to the core.The drying rate was higher for Melia than Eucalyptus under both drying conditions. The drying rate of Melia(ABP) was higher than Melia(BBP), however, the drying rate for Eucalyptus(ABP) was not significantly different from the BBP drying rate.
基金a part of M.Sc.thesis works funded by Forest Research Institute (Deemed) University,Dehradun (India)
文摘Plantation-grown progenies of Melia composita Willd.were studied for variability in several physical properties： density,radial and tangential shrinkage,longitudinal permeability of heartwood and sapwood.Furthermore,flat-sawn planks from each of the progeny were subjected to a quick-drying test for determination of kilndrying schedule.The mean density of the species was 0.39 g cm^（-3） and the wood may be categorized as light wood.Mean radial shrinkage（%） for the species was 2.8% with progeny-wise variation in radial shrinkage from 1.56 to 4.11%.Mean tangential shrinkage（%） for the species was 5.54% with progeny-wise variation in tangential shrinkage from 3.69 to 7.71%.The resultant tangentialradial shrinkage ratio was 1.98（less than two）,which suggests that the wood is relatively stable with respect to drying behavior.Mean sapwood and heartwood longitudinal permeability of the species were 3.38 and 2.02 Darcy,respectively.Higher longitudinal permeability of sapwood and heartwood indicate better drying and preservative properties of the species.Terazawa quick-drying test method suggests that the species is less susceptible to drying defects.During the test,only moderate checks and cracks were observed.A tentative kiln-drying schedule was recommended based on these results.
文摘Cemento-ossifying fibroma (COF) of maxilla is comparatively rare lesion of the maxillofacial region. There is often a misdiagnosis in the category of fibroosseous lesions, owing to an overlap of clinical, histological and radiographic features amongst the separate entities. We present a case of giant maxillary COF causing extensive disfiguration of the face, along with extensive review of the clinico-pathologic and treatment aspects of the fibro-osseous lesions.
文摘BACKGROUND The exponential rise in Coronavirus disease 2019(COVID-19)cases has resulted in an increased number of patients requiring prolonged ventilatory support and subsequent tracheostomy.With the limited availability of literature regarding the outcomes of COVID-19 patients with tracheostomy,we attempted to study the clinical characteristics and multiple parameters affecting the outcomes in these patients.AIM To determine all-cause mortality following tracheostomy and its association with various risk factors in COVID-19 patients.METHODS This retrospective study included 73 adult COVID-19 patients admitted to the ICU between 1 April,2020 and 30 September,2021 who underwent tracheostomy as a result of acute respiratory failure due to COVID-19.The data collected included demographics(age,sex),comorbidities,type of oxygen support at admission,severity of COVID-19,complications,and other parameters such as admission to tracheostomy,intubation to tracheostomy,ICU stay,hospital stay,and outcome.RESULTS This study included 73 adult patients with an average age of 52±16.67 years,of which 52%were men.The average time for admission to tracheostomy was 18.12±12.98 days while intubation to tracheostomy was 11.97±9 days.The mortality rate was 71.2%and 28.8%of patients were discharged alive.The mean duration of ICU and hospital stay was 25±11 days and 28.21±11.60 days,respectively.Greater age,severe COVID-19,mechanical ventilation,shock and acute kidney injury were associated with poor prognosis;however,early tracheostomy in intubated patients resulted in better outcomes.CONCLUSION Patients with severe COVID-19 requiring mechanical ventilation have a poor prognosis but patients with early tracheostomy may benefit with no added risk.We recommend that the timing of tracheostomy be decided on a case-by-case basis and a well-designed randomised controlled trial should be performed to elucidate the potential benefit of early tracheostomy in such patients.
基金supported by the Indian Government with Start-up Research Grant(2020/SRG/1742).
文摘Electric vehicles(EVs)are one of the more emerging and significant areas,representing the future of transportation.Moreover,the increased demand for EVs brings greater attention toward the development of the charging infrastructure.Therefore,this paper addresses the multifunctional charging system integrated with the grid,EV battery and household utilities.It presents an improved idea about the charging system with grid connection and its connection to the varying local nonlinear load.It consists of a voltage source converter(VSC)tied to the grid and bidirectional converter,which charges/discharges the battery and also regulates the constant voltage across the DC bus,where all the vehicles are connected for charging.It also shows the operations of charging/discharging the battery of EVs and the voltage and current profile across the battery as per the state of charge(SOC)limits.Moreover,the sparse constrained proportionate normalized least mean fourth(SCP-NLMF)based method is used to control the charging system by estimating the active component of load current.The derived mean square error(MSE)of load current is improved due to low convergence rates in later periods.The adaptation process becomes more accurate by mitigating the MSE error of load current to converge faster and the dynamic response is further improved.The simulated and tested results validate the accuracy and efficacy of the SCPNLMF technique and charging system.
基金Supported by the MPCST and SERB,India,for supporting through start-up research grant(SRG/2020/001742).
文摘In this work,we present a photovoltaic(PV)-based off-board charging system integrated with the grid using a voltage source converter(VSC).The control of the grid-tied off-board charger is derived from the joint logarithmic hyperbolic cosine robust sparse adaptive filter(JLHCAF)algorithm.This algorithm effectively tracks the fundamental component of the load current in a short duration,providing a good dynamic response.Due to its robustness against impulsive interference,the JLHCAF outperforms other sparsity-aware robust algorithms The cascaded proportional-integral(PI)controller is used to control the bidirectional buck-boost converter for electric vehicle(EV)charging/discharging,which acts in buck operation if the EV is being charged and in boost operation if it is discharged.The reference DC link voltage for the controller is derived by using adaptive MPPT technique.The bidirectional properties of the system enable various functions,including grid-to-vehicle(G2V),vehicle-to-grid(V2G),PV source-to-grid(PV2G),vehicle-to-home(V2H),and PV source-to-vehicle(PV2V)operations.Additionally,the system can supply power to critical nonlinear loads.The control strategy ensures compliance with the power quality requirements set by the IEEE standard,as demonstrated in the results.To validate the effectiveness of the proposed system,we conducted tests under dynamic conditions by disconnecting and reconnecting household loads.Furthermore,the off-board charging system was subjected to actual conditions,such as variations in solar PV insolation,and its steady-state performance was evaluated through simulation and laboratory experimental prototypes.The results,including total harmonic distortion(THD),support the validation of the developed charging system.
文摘The physio-chemical changes in concrete mixes due to different coarse aggregate(natural coarse aggregate and recycled coarse aggregate(RCA))and mix design methods(conventional method and Particle Packing Method(PPM))are studied using thermogravimetric analysis of the bydrated cement paste.A method is proposed to estimate the degree of hydration(a)from chemically bound water(WB).The PPM mix designed concrete mixes exhibit lower a.Recycled aggregate concrete(RAC)mixes exhibit higher and a after 7 d of curing,contrary to that after 28 and 90 d.The chemically bound water at infinite time(WBo)of RAC mixes are lower than the respective conventional concrete mixes.The lower WBo,Ca(OH)2 bound water,free Ca(OH)2 content and FT-IR analysis substantiate the use of pozzolanic cement in the parent concrete of RCA.The compressive strength of concrete and a cannot be correlated for concrete mixes with different aggregate type and mix design method as the present study confirms that the degree of hydration is not the only parameter which governs the macro-mechanical properties of concrete.In this regard,further study on the influence of interfacial transition zone,voids content and aggregate quality on macro-mechanical properties of concrete is needed.
