Constant Consumption Research Articles

Assessing the Optimum Level of Supplementation with Camelina Seeds in Ewes' Diets to Improve Milk Quality.

Camelina sativa seeds are rich in bioactive compounds such as polyunsaturated fatty acids (PUFA) and antioxidants, thus, their supplementation in ewes’ diets, may be an effective way to develop high nutritional dairy products. Therefore, the present study investigates the effect of the dietary inclusion of Camelina sativa seeds in ewes’ oxidative status and milk quality. Forty-eight dairy Chios ewes were divided into four homogenous groups and were fed individually. The concentrate of the control group (CON) had no inclusion of Camelina seeds, while the treatment groups (CSS6, CSS11, CSS16) were supplemented with 6%, 11%, and 16%, respectively. Including Camelina seeds in 6% and 11%, had no impact on milk performance, while in the CSS16, milk fat was significantly decreased compared to the CON. Supplementing Camelina seeds improved milk quality from a human health perspective by modifying the content of saturated fatty acid, the proportions of α-linolenic (C18:3 n-3), and C18:2 cis-9, trans-11 (CLA), and the ω6/ω3 ratio. Furthermore, the activity of catalase (CAT) was significantly increased in the CSS11 and CSS16, and superoxide dismutase (SOD) activity also significantly upsurged in the CSS16. Still, the levels of malondialdehyde (MDA) were significantly increased in the CSS11 compared to the CON and CSS6, and in the CSS16 compared to the CSS6. In CSS16, protein carbonyls were significantly increased. Finally, in the CSS-fed ewes, milk oxidative stability was fortified, as suggested by the modifications in the activities of SOD, CAT, and glutathione peroxidase (GSH-Px), in the antioxidant capacity, and the oxidative stress biomarkers. Consequently, the incorporation of 6% Camelina seeds in the concentrates of ewes improves milk’s fatty acid profile and oxidative status. However, more research is required regarding the possible negative effects of the constant consumption of Camelina seeds by ewes.

Comprehensive analysis of the treatment plant operation

Comparison of the content of manganese (II) andiron (III) ion sin river water and waste water, taking in to account the differentiation of the annual cycle, is carried out. It will allow moving to a comprehensive analysis of the treatment plant. The efficiency checking of the reduction of manganese (II) and iron (III) for a certain period was carried out, taking into account the constant consumption of the volume of water. The efficiency of wastewater treatment from manganese (II) ions is on average 31%, from iron (III) ions - 35%. The results obtained indicate the need for additional measures aimed at minimizing the content of manganese (II) and iron (III) ions in the process waters before the treatment plant. To minimize the content of these ions, it is necessary to select an effective and economic mode for purifying process waters. Purification of process waters from ions of manganese (II) and iron (III) was carried out using the following reagents: potassium permanganate; sodium sulfide; soda ash and sodium phosphate in stage-to-stage processing; suspensions of strong as well as weak milk of lime and brine sludge. For the purification of process waters from ions of manganese (II) and iron (III), industrial waste was proposed: the suspension of weak lime milk obtained after washing large quenching waste(large green coke - incompletely burned material) and used for transporting small quenching waste (small waste) to the sludge collector channel, and brine sludge suspension.

Upscale fermenter design for lactic acid production from cheese whey permeate focusing on impeller selection and energy optimization

This study focusses on the design and scale-up of industrial lactic acid production by fermentation of dairy cheese whey permeate based on standard methodological parameters. The aim was to address the shortcomings of standard scale-up methodologies and provide a framework for fermenter scale-up that enables the accurate estimation of energy consumption by suitable selection of turbine and speed for industrial deployment. Moreover, life cycle assessment (LCA) was carried out to identify the potential impacts and possibilities to reduce the operation associated emissions at an early stage. The findings showed that a 3000 times scale-up strategy assuming constant geometric dimensions and specific energy consumption (P/Vw) resulted in lower impeller speed and energy demand. The Rushton turbine blade (RTB) and LightninA315 four-blade hydrofoil (LA315) were found to have the highest and lowest torque output, respectively, at a similar P/Vw of 2.8 kWm−3, with agitation speeds of 1.33 and 2.5 s−1, respectively. RTB demonstrating lower shear damage towards cells (up to 1.33 s−1) was selected because it permits high torque, low-power and acceptable turbulence. The LCA results showed a strong relation between the number of impellers installed and associated emissions suggesting a trade-off between mixing performance and environmental impacts.

Current reused CMOS RF‐DAC for IoT applications

AbstractA current reused CMOS RF‐DAC with complementary current control, quadrature LO chain, and adaptive body injection mixer is presented in 0.18‐μm bulk CMOS process. The complementary current control leads to achieve good linearity by reducing the variation of output impedance. The proposed quadrature LO chain can achieve accurate signals in a wideband with constant amplitude and exact phase. The body injection mixer is implemented with simple high‐k resistor. It is measured with 5 and 5.3 GHz continuous‐wave (CW) signal, respectively. The measured constellation has 1024 points with constant current consumption of 73 mA.

Carbon dioxide bioconversion into single cell oils (lipids) in two reactors inoculated with Acetobacterium woodii and Rhodosporidium toruloides

Acetobacterium woodii was able to produce high concentrations of acetic acid, i.e., > 20 g/L, from CO2, in the presence of H2 as an energy source, which was favoured by maintaining a near-optimal pH of 7.8 in an automated bioreactor. This allows the mitigation of CO2 emissions for their conversion to acetic acid, which was then further used to produce lipids (single cell oils) by Rhodosporidium toruloides in the next assay. The yeast, grown on acetic acid, efficiently accumulated lipids in A. woodii’s medium, and further improved bioconversion would result in a highly promising process. Acetic acid inhibitory studies performed with R. toruloides, at different initial concentrations of the acid, using the fermented broth of A. woodii grown on CO2, showed that the yeast maintained a constant growth rate and substrate consumption rate up to acid concentrations of 15 g/L. Both rates remained roughly constant at higher initial acetic acid concentrations; except for a more extended lag phase observed in batch assays before the yeast entered in its exponential growth phase.

A compare research on third harmonic current control for five-phase permanent magnet synchronous motor

The injection of a third harmonic current can improve the electromagnetic torque output of the five-phase permanent magnet synchronous motor. In this paper, constant copper consumption and constant maximum current are used as constraints, and the influence of the ratio between the third harmonic current and the fundamental current on the electromagnetic torque under the two constraints is analyzed. The electromagnetic torque is the largest when the third harmonic current reference value is equal to the fundamental current reference value of ψf3/ψf times under the premise of the constant copper loss. On the premise that the maximum current is constant, the electromagnetic torque is the largest when the third harmonic current reference value is equal to the fundamental current reference value of kw/(6kw-kw3/3) times. On this basis, according to the vector amplitude, phase and action time, the changing trends of maximum voltage utilization rate with Vref3/Vref1 under three different kinds of methods are given. Finally, through the experimental platform, the control effects of the three kinds of SVPWM are compared under two constraint conditions.

Research on electrode position fuzzy control system of calcium carbide furnace based on constant power

The adjustment methods of calcium carbide furnace conditions include voltage regulator switches, electrode lifts, and changes in charge resistivity. For slight load changes, electrode lifts are commonly used. In order to have a positive effect on the control, furnace conditions and energy loss of the calcium carbide furnace, this paper proposes a fuzzy control method for the electrode lift of calcium carbide furnace based on constant power. By detecting the electrode current and electrode voltage, the electrode position is obtained indirectly, and then the fuzzy control idea is used to determine the control amount of the electrode lifting, and the control volume is converted into a pulse signal to act on the hydraulic solenoid valve to control the electrode lifting, so as to achieve a constant power consumption of the calcium carbide furnace the goal of. Simulation and practical applications show that this method can effectively avoid arc extinguishing and short-circuit phenomena, and has a certain positive effect on the operation of calcium carbide furnace, improvement of furnace conditions, and energy saving and consumption reduction.

A Comparison of RSOC-Battery Hybrid Energy Storage for Microgrids in the Netherlands and India

The importance of energy storage is steadily rising as electricity grids around the world become more reliant on intermittent renewable power sources such as solar PV and wind turbines. Apart from pumped hydro storage, which forms the bulk of existing energy storage, several other technologies are in development, such as batteries, super-capacitors, flywheels and synthetic e-fuels. Li-ion batteries are highly efficient and dynamic, while e-fuels have many advantages for large-scale seasonal storage. Reversible solid oxide cells (rSOC) are efficient electrochemical devices, which can play an important role in energy storage in the form of e-fuels in the near future. This paper seeks to show the advantages of rSOC systems in long-term energy storage. In particular, it seeks to compare the capital cost of a hybrid system to a purely Li-ion battery system.This paper focuses on the design of energy storage for isolated sustainable micro-grids. A hybrid system is designed, using Li-ion batteries for instantaneous grid balancing, and rSOC system for long-term storage in the form of hydrogen. The paper also focuses on the effect of the wind-solar energy mix and climate. For temperate and cloudy climates, Groningen in the Netherlands is used as an example. The Netherlands has a renewable energy mix of around 70% wind and 30% solar. For sunny tropical climates, Jodhpur in India is used, and India has a renewable energy mix of around 55% wind and 45% solar. Using hourly local data for solar irradiation and wind velocities, a simple algorithm is developed for system sizing. The generation as well as storage systems are sized for a constant consumption load of 20 kW (a constant load is considered to be a reasonable assumption for industrial loads, for example). The capital cost calculation includes the wind turbine(s), solar panels, battery bank, rSOC stack, and compressed hydrogen tank.The results show that the use of an rSOC-hydrogen module in a hybrid-energy storage system leads to significant capital cost reduction compared to a purely Li-ion battery-based system. As expected, this reduction is a result of the fact that power and energy-storage capacities are decoupled in an rSOC/e-fuel system, which means that a small rSOC stack can be used with a large tank, which is suitable for long-term seasonal storage. Hydrogen tanks also cost significantly less than batteries for the same energy capacity. The cost reduction for Jodhpur is more significant than for Groningen.The study also shows the significant effect of the local energy mix on the design of energy storage systems. Naturally, Jodhpur has more solar radiation and less seasonal variation in solar energy. But contrary to initial expectations, tropical Jodhpur requires larger energy seasonal storage facilities than temperate Groningen. This is because the small seasonal solar variation in Jodhpur is further compounded by the seasonal wind pattern, where the wind is strong in summer and weak in winter. On the other hand, the wind patterns are much more stable in Groningen, which largely neutralises the solar variation, especially since wind makes up 70% of the energy mix in Groningen. Figure 1

Hypoxia-responsive nanoreactors based on self-enhanced photodynamic sensitization and triggered ferroptosis for cancer synergistic therapy

BackgroundPhotodynamic therapy (PDT), a typical reactive oxygen species (ROS)-dependent treatment with high controllability, has emerged as an alternative cancer therapy modality but its therapeutic efficacy is still unsatisfactory due to the limited light penetration and constant oxygen consumption. With the development of another ROS-dependent paradigm ferroptosis, several efforts have been made to conquer the poor efficacy by combining these two approaches; however the biocompatibility, tumor-targeting capacity and clinical translation prospect of current studies still exist great concerns. Herein, a novel hypoxia-responsive nanoreactor BCFe@SRF with sorafenib (SRF) loaded inside, constructed by covalently connecting chlorin e6 conjugated bovine serum albumin (BSA-Ce6) and ferritin through azobenzene (Azo) linker, were prepared to offer unmatched opportunities for high-efficient PDT and ferroptosis synergistic therapy.ResultsThe designed BCFe@SRF exhibited appropriate size distribution, stable dispersity, excellent ROS generation property, controllable drug release capacity, tumor accumulation ability, and outstanding biocompatibility. Importantly, the BCFe@SRF could be degraded under hypoxia environment to release BSA-Ce6 for laser-triggered PDT, ferritin for iron-catalyzed Fenton reaction and SRF for tumor antioxidative defense disruption. Meanwhile, besides PDT effects, it was found that BCFe@SRF mediated treatment upon laser irradiation in hypoxic environment not only could accelerate lipid peroxidation (LPO) generation but also could deplete intracellular glutathione (GSH) and decrease glutathione peroxidase (GPX4) expression, which was believed as three symbolic events during ferroptosis. All in all, the BCFe@SRF nanoreactor, employing multiple cascaded pathways to promote intracellular ROS accumulation, presented remarkably outstanding antitumor effects both in vitro and in vivo.ConclusionBCFe@SRF could serve as a promising candidate for synergistic PDT and ferroptosis therapy, which is applicable to boost oxidative damage within tumor site and will be informative to future design of ROS-dependent therapeutic nanoplatforms.Graphic abstract

Consuming conflict as Tamil consciousness: the case of second-generation British Sri Lankan Tamils

ABSTRACT A long-running conflict is wounding for generations, not only by sustaining an affective sense-making between different geolocations but also by binding diasporic communities through the conflict’s temporality of pain, violence and loss as enduring legacies. Long-running conflicts leave wounds, binding generations through an allotropic process in which the trauma is experienced second-hand and consumed through the circulation of the conflict in a myriad of cultural forms. This paper reveals the findings of a study conducted among second-generation British Sri Lankan youths to understand conflict as a site of constant consumption and domestication, yielding an affective sphere of sense making. In particular, the paper traces how the consumption of conflict is reified and temporally enlarged through the interactions between first and second generations, transnational networks and peers as well as media technologies in mediating Tamil identity and consciousness. This affective sphere induced through second-hand trauma is continuously sustained, renewed and negotiated in lending to the process of identity construction and the moral imagination of a homeland.

Residential electricity consumption and household characteristics: An econometric analysis of Danish smart-meter data

Households are heterogeneous customers that consume different amounts of electricity for different purposes at different hours of the day. Understanding how the level and timing of electricity consumption is related to household characteristics is important in planning production and grid capacities and in designing policies.Linking Danish smart-meter data for 2017 to detailed household characteristics derived from administrative registers, we analyse how the level and profile of hourly electricity consumption is related to these characteristics. In addition, we examine to what extent having a flat rate for electricity implies cross-subsidies between residential customers in Denmark.We find that both the level and timing of consumption vary significantly with household characteristics, mainly the type of dwelling, its heating technology, its use of electric vehicles, and the number and age of the adults and children who live there, all of which affect the level and timing of consumption. Assuming hourly pricing with constant consumption rates, the average price per kWh paid by different categories of household varies only marginally. That is, the flat rate presently seen by Danish households implies limited cross-subsidies between groups of residential customers. Consequently, introducing real-time pricing for Danish residential customers should not pose serious redistribution concerns and would improve economic efficiency.

DRIVER OUTPUT IMPEDANCE CALIBRATION SYSTEM WITH COMPARATOR UNIT OFFSET CANCELLATION

In modern integrated circuits, the channel length of the transistors is reduced, and the supply voltages are also reduced. But the threshold voltages of the transistors cannot be reduced so quickly due to the physical properties of the materials used, which decreases the operating range of the transistors and makes noises comparable to them. Therefore, it is necessary to eliminate the influence of noise sources in the circuits, in particular, reflections between the transmission line and the output of the transmitter. A system is proposed for calibrating the output impedance of the transmitter based on an accurate external resistor with comparator unit offset voltage compensation. Existing analog and reference frequency based solutions have key disadvantages such as the inability to compensate the offset voltage after the integrated circuit is fabricated, and the distribution of the calibration voltage across the Input/Output device and constant power consumption during the operation. The proposed circuit includes a high-precision digital-to-analog converter to compensate the comparator offset voltage. It generates calibration codes for the pull-up and pull-down parts of the transmitter output buffer, and provides fine tuning of the output impedance. The circuit was modeled using 16 nm FinFET process elements and simulated with HSPICE simulator.

Соціально-екологічна та медична проблеми нестачі йоду серед населення України

Aim. Study of iodine supply in different segments of the population throughout Ukraine, establishment of the morbidity level caused by iodine deficiency, analysis of preventive measures and their effectiveness and development of adequate ways of mass, group and individual prophylaxis of iodine deficiency in the body, which will reduce morbidity in areas of endemic iodine deficiency. The article considers the most important results of long-term epidemiological studies of iodine supply in different categories of the population of almost all regions of Ukraine. Significant volume of work was performed with the support of the Ministry of Healthcare of Ukraine, UNICEF Ukrainian office, and the CDC in Atlanta (USA), which for more than 19 years has provided external quality control of the study of iodine status of the population of Ukraine. The data on iodine content in food and biological fluids of the population affected by the Chernobyl accident are given and the dependence of the irradiation dose of the thyroid on the body supply with stable iodine and on the optimization of the latter after the adoption of the State Programme for Iodine Deficiency Prevention for 2002–2005 is shown. The effectiveness of mass iodine prophylaxis by using universally iodized table salt is emphasized. The article presents data on suggested and implemented ways of mass, group and individual iodine prophylaxis, studies of their effectiveness and shows the positive dynamics of changes in providing the population with dietary iodine. The need for constant consumption of food products with sufficient iodine content, including iodized salt, is proven. Significant changes in the prevalence and incidence of thyroid pathology, socio-ecological and medical benefits of prevention of iodine-dependent disorders are described. The article was prepared as a scientific information material for family doctors, endocrinologists, obstetricians and gynaecologists, hygienists, the public, the Ministry of Healthcare of Ukraine in connection with the need for a legislative solution to the prevention of iodine-dependent disorders in Ukraine. Materials and Methods. To study the problem and assess the state of iodine deficiency in Ukraine the criteria recommended by the WHO and the United Nations Children’s Fund (UNICEF) were applied for the first time, a method for determining the iodine content in the body was developed and implemented, which allowed to join the international “Equip” system of iodine supply control in the world and in Ukraine. This made it possible to move from indirect to direct methods of determining the intake of iodine in the body. Conclusions. A detailed study of iodine supply in different segments of the population of Ukraine proved the negative effects of iodine deficiency on health; in particular, it was found that the overall decrease in productivity of the generation of children in iodine deficiency populations is 5%. Measures to eliminate iodine-dependent disorder among the population of Ukraine have been developed and implemented. The development and production of iodized food salt, adequate to the needs of the population, has been carried out. The result of these measures, developed and implemented to eliminate iodine-dependent disorders and to improve the nation’s intelligence, is, according to the official data, the improvement of iodine supply of the population, significant reduction in the number of thyroid disorders, especially among those affected with 131I, which, even just because of this indicator, has significant social-economic effect. Key Words: Chernobyl accident, iodine deficiency, iodized salt, population, prevention, regions.

Testing for structural break in aggregated consumption function of Russian households

The paper considers a simple aggregated consumption function for Russian economy in which households consume a constant fraction of a permanent income. The value of this fraction is estimated by households within the framework of the adaptive expectations process based on the dynamics of GDP at constant consumption prices. Testing for a structural break at an unknown date in the parameter of the propensity to consume is performed. The results of econometric estimation, taking into account the presence of an endogeneity in the regression equation, demonstrate that after 2014 there was a structural break, as a result of which the parameter of the propensity to consume of permanent GDP decreased by 6.5—9.2%.

Fructan Structure and Metabolism in Overwintering Plants.

In northern regions, annual and perennial overwintering plants such as wheat and temperate grasses accumulate fructan in vegetative tissues as an energy source. This is necessary for the survival of wintering tissues and degrading fructan for regeneration in spring. Other types of wintering plants, including chicory and asparagus, store fructan as a reserve carbohydrate in their roots during winter for shoot- and spear-sprouting in spring. In this review, fructan metabolism in plants during winter is discussed, with a focus on the fructan-degrading enzyme, fructan exohydrolase (FEH). Plant fructan synthase genes were isolated in the 2000s, and FEH genes have been isolated since the cloning of synthase genes. There are many types of FEH in plants with complex-structured fructan, and these FEHs control various kinds of fructan metabolism in growth and survival by different physiological responses. The results of recent studies on the fructan metabolism of plants in winter have shown that changes in fructan contents in wintering plants that are involved in freezing tolerance and snow mold resistance might be largely controlled by regulation of the expressions of genes for fructan synthesis, whereas fructan degradation by FEHs is related to constant energy consumption for survival during winter and rapid sugar supply for regeneration or sprouting of tissues in spring.

Design features of negative feedback and power smoothing filter of the DC / DC converter with pulse loads for transmitter-receiver modules of active electronically scanned arrays

The fundamental difference of the voltage converter of the secondary power supply source for the transmitter-receiver modules of active electronically scanned arrays with impulse load and variable duty cycle from traditional voltage converters that constantly consume power from the primary network is shown. Methods for improving the quality of transient processes in voltage converter with constant power consumption during start-up by soft start are not applicable to improve the quality of transients in periodic current pulses caused by a pulsed load. Since any ripples, noises, instabilities in the power supply of the transmitter-receiver modules of active electronically scanned arrays operating in a linear mode lead to parasitic amplitude modulation of the emitted signal and to a deterioration in the quality of selection and target tracking, very strict requirements are imposed on the quality of the transmitter-receiver modules supply voltage (voltage ripple kп ≤ 0,5 %, the amount of overshoot of the output voltage sU ≤ 2 %, etc.). The article shows that such a quality of the output voltage with a pulsed load of the transmitter-receiver modules of active electronically scanned arrays can be obtained using a lower-type voltage converter, with a double-circuit negative feedback for the output voltage and current of the inductor, with a storage capacitor and with a power smoothing filter with the characteristics of Chebyshev and Butterworth. The work investigated the influence of the negative feedback depth on the output voltage and current of the smoothing filter choke, the value of the storage capacitor capacity, the type and parameters of the smoothing filter, and recommendations were given to select their optimal values, at which the required quality of the supply voltage for the transmitter-receiver modules of active electronically scanned arrays was ensured, taking into account the minimization of their dimensions.

Synergistic algicidal effects of combined UV-LED/chlorine treatments on Tetraselmis sp.: Optimization and mode-of-action

• Disinfection of Tetraselmis sp. using UV-LEDs, chlorine and UV-LED/chlorine. • UV-LED/chlorine promotes algal inactivation compared to individual treatments. • UV-LED/chlorine disinfection is a wavelength-dependent process. • UV 285 /chlorine showed the best inactivation effect and the lowest energy-efficiency. • Radicals were found to play an important role in the synergy treatment. Unwanted proliferation of and adhesion by microalgae, as involved in fouling and species invasion, are important problems across many maritime operations and coastal industrial activities. The algicidal mechanisms of ultraviolet light-emitting diodes (UV-LEDs) and the synergistic algicidal effects between UV-LEDs and chlorine treatments in seawater were investigated in this study. Tetraselmis sp. was employed as the challenge organism. Five UV wavelengths (265, 280, 285, 300 and 315 nm) and three chlorine dosages (0.6, 0.8 and 1 mg L −1 ) were examined in a factorial experiment to optimize the disinfection performance achieved by combined UV-LED/chlorine treatments in seawater. Overall, the combined treatments showed a more effective inactivation of the microalgae than did the single treatments. Treatment with UV 285 combined with 0.8 mg L −1 chlorine resulted in 3.12-log inactivation at 100 mJ cm −2 (i.e. 2.34 Einsteins L -1 , 67 s). This optimal combination showed a higher inactivation rate constant and lower energy consumption (E E,2 ) than did the other treatments. The contribution of UV-LEDs, chlorine and hydroxyl radical (·OH) in the inactivation of Tetraselmis sp. by the combined UV-LED/chlorine disinfection process was investigated to illustrate the mechanism of this synergistic process, the results indicated that ·OH generated by photolysis were not the only contributors to the inactivation of the microalgae. Although a UV 300 /chlorine treatment demonstrated the highest chlorine photolysis rate, the inactivation constant of this treatment was lower than that of UV 285 /chlorine. These results demonstrated a synergistic algicidal effect of the combined disinfection system caused by exposure to the 285 nm UV-LED and low dosages of chlorine, which could provide an important basis for further developments and possibly industrial applications in the future.

Effect of impeller type and scale-up on spatial distribution of shear rate in a stirred tank

The main spatial distribution features of shear rate in a stirred tank operated with five different radial and axial flow impellers were presented with particle image velocimetry (PIV) experiments. Not only the average shear rate in the whole tank but also the local value in vicinity of impeller increases linearly with impeller speed. Furthermore, the shear coefficient ( K s,imp ) at the impeller outlet is linearly related to the impeller flow number ( N q ) and decreases with the increase of N q in general at the constant power consumption per unit volume ( P v ). During scale-up based on the constant P v and geometric similarity, CFD results show that the volume-averaged shear rate ( γ avg ) for RDT decreases faster than that of other impellers with the impeller tip velocity ( U tip ). The novel multi-blade combined (MBC) impeller with the increased height-to-diameter ratio of the stirred tank is able to more effectively improve the distribution uniformity of shear rate at the same P v after scale-up. These studies provide a data basis for selecting the impeller types and improving the shear rate environment in large-scale stirred tank.

1.0 V-0.18 µm CMOS Tunable Low Pass Filters with 73 dB DR for On-Chip Sensing Acquisition Systems

This paper presents a new approach based on the use of a Current Steering (CS) technique for the design of fully integrated Gm–C Low Pass Filters (LPF) with sub-Hz to kHz tunable cut-off frequencies and an enhanced power-area-dynamic range trade-off. The proposed approach has been experimentally validated by two different first-order single-ended LPFs designed in a 0.18 µm CMOS technology powered by a 1.0 V single supply: a folded-OTA based LPF and a mirrored-OTA based LPF. The first one exhibits a constant power consumption of 180 nW at 100 nA bias current with an active area of 0.00135 mm2 and a tunable cutoff frequency that spans over 4 orders of magnitude (~100 mHz–152 Hz @ CL = 50 pF) preserving dynamic figures greater than 78 dB. The second one exhibits a power consumption of 1.75 µW at 500 nA with an active area of 0.0137 mm2 and a tunable cutoff frequency that spans over 5 orders of magnitude (~80 mHz–~1.2 kHz @ CL = 50 pF) preserving a dynamic range greater than 73 dB. Compared with previously reported filters, this proposal is a competitive solution while satisfying the low-voltage low-power on-chip constraints, becoming a preferable choice for general-purpose reconfigurable front-end sensor interfaces.

Can Low Retirement Savings Be Rationalized?

Simple presentations of the life cycle model often suggest a constant level of real consumption in retirement. Similarly, financial planners commonly suggest that people save for retirement in such a way as to enable them to maintain a level retirement standard of living equal to their standard of living while working. However, constant consumption with age is only optimal under the precise and unlikely condition that the subjective rate of time preference is equal to the real interest rate. Most people exhibit a positive rate of pure time preference, and additionally discount the future by both mortality and morbidity risks. In comparison, the real interest rate is roughly 0%—and the term structure of interest rates suggests this condition is likely to persist. These considerations suggest that optimal consumption in the life cycle model declines with age. This finding has major implications for optimal retirement saving. For instance, we find that for many, perhaps most, people in the bottom half of the lifetime earnings distribution, it is optimal to spend out their retirement wealth well before death and to live on Social Security alone after that. Very low earners may find it optimal to not engage in retirement saving at all. <b>TOPICS:</b>Long-term/retirement investing, portfolio theory <b>Key Findings</b> ▪ Under plausible assumptions, optimal consumption in the life cycle model declines with age. ▪ For many people in the bottom half of the lifetime earnings distribution, it is optimal to spend out retirement wealth well before death and live on Social Security alone after that. ▪ These results stand in contrast to standard financial planning advice that people save for retirement in such a way as to enable them to maintain a level retirement standard of living equal to their standard of living while working.