Lifetime Expectancy Research Articles

Extended lifetime expectancy in schizophrenia, role of measurement based care

Lifespan in schizophrenia spectrum disorders (SSD) is up to 20 years shorter than average. Introduction of new antipsychotic pharmaceuticals has not made any major improvement. Parallel care is provided as usual standard care (USD) in out-patients settings. The study aim was to evaluate if inclusion of Measurement Based Care (MBC) may prolong patients' lifespan. In total, 171 patients were followed with annual semi-structured examinations of psychiatric status, social situation, and somatic illnesses over 20 years, by case managers. Findings indicate that MBC contributed to prolonged lifespan in SSD from 55.6 to 69.4 years from beginning to end of the study.

A Liquid Well Barrier Element for Temporary Plug and Abandonment Operations: A Breakthrough Approach

Plug and abandonment (P&A) operations demand valuable time and resources for operational procedures and materials to establish the well barrier element. This study aims to investigate the application of a water-based fluid as a liquid well barrier element for temporary abandonment, based on estimates of its lifespan and the survival probabilities of downhole temperatures acquired through accelerated life tests. To achieve this, the water-based formulation was tested and exposed to 95, 110, 140, and 150 °C temperatures for time intervals ranging from 1 to 10 days. After the temperature exposure, the fluid properties were verified, and failure was detected by accounting for any deterioration in rheological parameters and/or a substantial increase in filtrate volume. A statistical analysis of the failure data was performed in RStudio 4.1.3 software using the Weibull Model, and the fluid average lifespans and survival probabilities were estimated for the P&A temperatures. The results obtained demonstrate that the degradation of the fluid was only observed for 140 and 150 °C temperatures. According to the results, the fluid is a promising alternative for temporary abandonment until 80 °C, with no need for monitoring once its lifetime expectation exceeds three years at this temperature. For downhole temperatures above 80 °C, the fluid is a possible alternative, however, the operation’s maximum time and monitoring requirements should consider reliability metrics for each temperature.

Influence of Hydrogen on the Failure Mechanism of Standard Duplex Stainless Steel X2CrNiMoN22-5-3 Exposed to Corrosion Fatigue

IIn a geothermal environment, cathodic protection is employed to improve resistance against corrosion fatigue. However, during the cathodic reactions under applied potential, hydrogen is generated and assimilated, leading to a reduced lifetime expectancy of high-alloyed steels. The corrosion fatigue mechanism of a standard duplex stainless steel X2CrNiMoN22-5-3 (1.4462) specimen loaded with hydrogen was studied in a corrosion chamber specifically designed for the purpose, surrounded by the electrolyte of the Northern German Basin at 369 K. The microstructural reactions resulting in hydrogen incorporation significantly decrease the number of cycles to failure of the specimen. This reduction is attributed to hydrogen enhancing crack propagation and causing early failure, primarily due to the deterioration of the mechanical properties of the ferritic phase rather than corrosion reactions or corrosive degradation.

Factors influencing deprescribing in primary care for those towards the end of life: A qualitative interview study with patients and healthcare practitioners.

For people with limited lifetime expectancy, the benefit of many medications may be outweighed by their potential harms. Despite the relevance of reducing unnecessary medication use, deprescribing is poorly enacted in primary care practice. This study aims to describe factors, as identified by primary care professionals and patients, that influence deprescribing in the last phase of life. Semi-structured interviews were conducted and analysed using a thematic approach. This study was performed in primary care settings, including general practices, hospices and community care teams in The Netherlands. Purposefully identified primary care professionals (general practitioners, pharmacists, nurses) and patients with limited lifetime expectancy due to advanced chronic illness or cancer and their caretakers were interviewed. Three themes emerged detailing factors influencing deprescribing in the last phase of life in primary care: (1) non-maleficence, the wish to avoid additional psychological or physical distress; (2) reactive care, the lack of priority and awareness of eligible patients; and (3) discontinuity of care within primary care and between primary care and specialty care. Deprescribing is an incremental process, complicated by the unpredictability of life expectancy and attitudes of patients and health care professionals that associate continued medication use with clinical stability. Opportunities to facilitate the deprescribing process and its acceptance include the routinely systematic identification of patients with limited life expectancy and potentially inappropriate medications, and normalisation of deprescribing as component of regular primary care, occurring for all patients and continuing into end-of-life care.

Investigating North Sea Precipitation Variability: Implications for Offshore Wind Energy Siting and Condition Assessments

Rain-driven wind turbine blade erosion, particularly in offshore locations, has been observed as early as within 5 to 7 years of turbine operation, which is below the lifetime expectancy design age of 20 to 25 year. Due to the harsh atmospheric conditions offshore, the preservation of wind turbine blade integrity has become a fundamental necessity. To address this challenge, we compare precipitation maps from two distinct sources (satellite data and a reanalysis product) over 12 years in the region of the North Sea, and we pursue insights into local weather patterns through temporal analysis. This integrated approach enhances the understanding of offshore conditions by focusing on precipitation and wind speed data analysis in time and space. This enables more efficient wind farm planning, operation and maintenance, as well as wind farm siting via informed decisions that account for the risk of rain-driven blade erosion and allow for mitigation measures.

UAV-based solution for extending the lifetime of IoT devices: efficiency, design and sustainability

Internet of Things technology is named as a key ingredient in the evolution towards digitization of many applications and services. A deployment based on battery-powered remote Internet of Things (IoT) devices enables easy installation and operation, yet the autonomy of these devices poses a crucial challenge. A too short lifespan is undesirable from a functional, economical, and ecological point of view. This paper presents a unmanned aerial vehicle (UAV)-based approach to recharge remote Internet of Things (IoT) nodes. An in-depth study of the charging efficiency and optimization of key parameters, and measurements-based verification, is reported on. An actual corresponding design and implementation of the full UAV-based charging system and its proof-of-concept validation are presented. Finally, the sustainability of the proposed solution is discussed. The results presented in this paper hence confirm that the proposed UAV-based approach and design are functionally successful and efficient charging can be achieved, provided the constraints and challenges coming with the approach are adequately dealt with. Moreover, it comes with an overall reduction in ecological footprint for IoT applications relying on battery-powered nodes in need of medium energy and/or considerable lifetime expectation (5 years or more).

Evaluation of Chemical and Impacts of Radionuclides in Borehole Waters in Igbajo Town, Osun State, Nigeria

Water is a universal solvent on earth and sources such as wells, rivers, springs, boreholes, and other freshwater bodies typically serve as a pathway for contaminants to enter the ecosystem while also supplying water for domestic and drinking purposes. The activity concentrations of radionuclides in borehole water in Igbajo town were assessed using gamma-ray spectroscopy, so as to effectively determine the degree of radiological risk to the environment and its inhabitants, the outcomes were used to calculate all the radiological impact parameters. The activity concentrations obtained for 40K, 238U and 232Thranged from 7.25±0.60 to 62.15±4.48Bq.L–1; 3.08±0.45 to 15.24±3.07 Bq.L–1and 1.08±1.10 to 17.75±1.59 Bq.L–1 and with average values of 23.12±1.59 Bq.L–1, 6.27±2.01 Bq.L–1 and 7.01±0.89 Bq.L–1 respectively. The Annual Effective Dose (AED) for ingested radionuclide in drinking water for an adult was1.4872 μSv.yr–1. The Radium Equivalent Activity Index, Raeq obtained was 34.9186 Bq.L–1. The estimated hazard indices Hint and Hext were 0.04876 and 0.06574 respectively. The Excess Lifetime Cancer Risk, ELCR (x10–6) was 5205.15. With a lifetime expectancy of 70 years, this high value suggests that there is a high chance of developing cancer.The value of the Annual Gonadal Equivalent Dose, AGED in the water was 55.9175μSv.yr–1. The estimated Gamma Index, Iγ was0.1273 mSv.yr–1. There is a significant health hazard to the environment and people living in the area owing to the radioactivity contents and radiological impact parameters. Hence, the need for urgent attention and means to prevent hazards which the overdose could cause.

Design modifications and evaluation of the silicone artificial finger joints.

There are many reasons that could lead to finger joint arthroplasty, and the most familiar reason is osteoarthritis. Silicone finger joint are the most commonly used implants. However, these implants might fracture with time and cause wear which will lead to chronic inflammation and synovitis for the patient and then implant failure. The aim of this study is to improve the design of the silicone finger joint and simulate the different designs using finite element analysis (FEA) simulation. Three different designs were drawn and FEA has been used in this study using Solidworks software. The first design is the silicone finger joint design without any modification, the second one is modified design with added ribs to the junction of distal stem and hinge and the third design was added filler material inside the body of the artificial joint. An axial force with 625N that was applied on the upper part of the distal stem which is nearly represents the maximum value of the grip strength for normal males. The results showed improvement on the design in which the concentrated stress at the junction of the distal stem and hinge of the design was distributed. In addition, the Von Mises stress was stable for the modified design with added ribs and the added filler material designs after 15°. The design modification could improve the stress distribution and stability of the artificial finger joint and increase the lifetime expectancy of these implants.

Molecular fingerprint of gilthead seabream physiology in response to pollutant mixtures in the wild

The increase in trace element concentrations in the aquatic environment due to anthropogenic activities, urges the need for their monitoring and potential toxicity, persistence, bioaccumulation, and biomagnification at different trophic levels. Gilthead seabream is a species of commercial importance in the Mediterranean Sea, both for the aquaculture and fisheries sectors, however very little is known about their trace element contamination accumulation and the resulting effect on their health status. In the present study, 135 juveniles were collected from seven coastal lagoons known to be essential nursery areas for this species. We measured seventeen different inorganic contaminants at the individual level in fish muscle (namely Al, As, Be, Bi, Cd, Cr, Cu, Hg, Li, Ni, Pb, Rb, Sb, Sr, Ti, Tl and Zn). Our results revealed the accumulation of multiple trace elements in individuals and distinct contamination signatures between lagoons which might lead to contrasted quality as nurseries for juveniles of numerous ecologically and economically relevant fish species in addition to seabreams. We further evaluated the potential adverse effect of these complex contamination mixtures on the liver (the main organ implicated in the metabolism of xenobiotics) and red muscle (a highly metabolic organ) using a proteomic approach. Alterations in cellular organization pathways and protein transport were detected in both tissues (albeit they were not similarly regulated). Chromosome organization and telomere maintenance in the liver appeared to be affected by contaminant mixture which could increase mortality, age-related disease risk and shorter lifetime expectancy for these juveniles. Red muscle proteome also demonstrated an upregulation of pathways involved in metabolism in response to contamination which raises the issue of potential energy allocation trade-offs between the organisms’ main functions such as reproduction and growth. This study provides new insights into the cellular and molecular responses of seabreams to environmental pollution and proposed biomarkers of health effects of trace elements that could serve as a starting point for larger-scale biomonitoring programs.

Investigating the Chemical Stability of Electrospray Plumes During Particle Collisions

Electrospray thrusters fulfill the main propulsion requirements for long-term small-satellite missions. However, the molecules present in the plume are susceptible to collisions, chemical reactions, and fragmentation, which may introduce different new species with various mass-to-charge ratios inside the plume. Prediction of the byproducts that appear upon collisions is of prime importance to predicting the evolution of the plume and estimating the performance and the lifetime expectancy of the thruster. In this work, we use molecular dynamics simulations to investigate monomer–neutral collisions at different impact configurations, impact energies, and impact parameters, and we provide the mass spectra of the resulting species. We predict that 1) collisions within a center-of-mass distance of 6 Å can result in momentum exchange and molecular fragmentation, 2) higher-energy impacts produce more byproducts, and 3) heavy molecules (e.g., 1-ethyl-3-methylimidazolium [EMI] and BF4) are more likely to result from weak collisions (<30 eV), whereas light molecules (e.g., H, F, and CH3) are more likely to result from strong collisions. Collisional fragmentation is shown to negatively affect key performance indicators, including reductions in thrust, specific impulse, and propulsive efficiency. This phenomenon potentially accounts for the observed discrepancies in experimental measurements of current and mass loss rates.

Corrosion Fatigue of Standard Duplex Stainless Steel X2CrNiMoN22-5-3 under Rotation Bending Load in Northern German Basin Environment

Standard duplex stainless steel X2CrNiMoN22-5-3 is resistant to both, corrosion and mechanical stress, but corrosion fatigue (CF) lowers the lifetime expectancy in a geothermal environment such as the Northern German Basin. Laboratory experiments used the in-situ electrolyte at 369 K in a specifically designed corrosion chamber applying rotation bending cyclic load to failure. CF behaviour was compared to pure push-pull load. Corrosion kinetics are independent of the load applied. Failure is initiated by pits resulting in mechanical degradation. Increased thickness of the passivating layer surrounding pits enhances degradation or delamination. Also, sharp notches located along the pit edge increase notch effects and stress concentration consequently leading to fast crack propagation and early failure.

Different Types of Patient Health Information Associated With Physician Decision-making Regarding Cancer Screening Cessation for Older Adults

Although guidelines use limited life expectancy to guide physician decision-making regarding cessation of cancer screening, many physicians recommend screening for older adults with limited life expectancies. Different ways of presenting information may influence older adults' screening decision-making; whether the same is true for physicians is unknown. To examine how different ways of presenting patient health information are associated with physician decision-making about cancer screening cessation for older adults. A national survey was mailed from April 29 to November 8, 2021, to a random sample of 1800 primary care physicians and 600 gynecologists from the American Medical Association Physician Masterfile. Primary care physicians were surveyed about breast, colorectal, or prostate cancer screenings. Gynecologists were surveyed about breast cancer screening. Using vignettes of 2 older patients with limited life expectancies, 4 pieces of information about each patient were presented: (1) description of health conditions and functional status, (2) life expectancy, (3) equivalent physiological age, and (4) risk of dying from the specific cancer in the patient's remaining lifetime. The primary outcome was which information was perceived to be the most influential in screening cessation. The final sample included 776 participants (adjusted response rate, 52.8%; mean age, 51.4 years [range, 27-91 years]; 402 of 775 participants were men [51.9%]; 508 of 746 participants were White [68.1%]). The 2 types of information that were most often chosen as the factors most influential in cancer screening cessation were description of the patient's health or functional status (36.7% of vignettes [569 of 1552]) and risk of death from cancer in the patient's remaining lifetime (34.9% of vignettes [542 of 1552]). Life expectancy was chosen as the most influential factor in 23.1% of vignettes (358 of 1552). Physiological age was the least often chosen (5.3% of vignettes [83 of 1552]) as the most influential factor. Description of patient's health or functional status was the most influential factor among primary care physicians (estimated probability, 40.2%; 95% CI, 36.2%-44.2%), whereas risk of death from cancer was the most influential factor among gynecologists (estimated probability, 43.1%; 95% CI, 34.0%-52.1%). Life expectancy was perceived as a more influential factor in the vignette with more limited life expectancy (estimated probability, 27.9%; 95% CI, 24.5%-31.3%) and for colorectal cancer (estimated probability, 33.9%; 95% CI, 27.3%-40.5%) or prostate cancer (28.0%; 95% CI, 21.7%-34.2%) screening than for breast cancer screening (estimated probability, 14.5%; 95% CI, 10.9%-18.0%). Findings from this national survey study of physicians suggest that, in addition to the patient's health and functional status, the cancer risk in the patient's remaining lifetime and life expectancy were the factors most associated with physician decision-making regarding cancer screening cessation; information on cancer risk in the patient's remaining lifetime and life expectancy is not readily available during clinical encounters. Decision support tools that present a patient's cancer risk and/or limited life expectancy may help reduce overscreening among older adults.

Cost-effectiveness analysis of molecular testing in minimally invasive samples to detect endometrial cancer in women with postmenopausal bleeding

IntroductionNew approaches are being developed to early detect endometrial cancer using molecular biomarkers. These approaches offer high sensitivities and specificities, representing a promising horizon to develop early detection strategies.ObjectiveTo evaluate the effectiveness and cost-effectiveness of introducing molecular testing to detect endometrial cancer in women with postmenopausal bleeding compared to the current strategy using the national healthcare service perspective.MethodsA Markov model was developed to assess the two early detection strategies. The model predicts the number of hysterectomies, lifetime expectancy, quality-adjusted life-years, endometrial cancer prevalence and incidence, mortality from endometrial cancer and the lifetime cost of screening, diagnosis, and treatment. Strategies were compared using the incremental cost-effectiveness ratio.ResultsThe molecular strategy reduces 1.9% of the overall number of hysterectomies and the number of undetected cancer cases by 65%. Assuming a molecular test cost of 310€, the molecular strategy has an incremental cost of -32,952€ per QALY gained, being more effective and less expensive than the current strategy.ConclusionsThe introduction of molecular testing to diagnose endometrial cancer in women presenting postmenopausal bleeding provides more health benefit at a lower cost, and therefore has the potential to be cost-effective.

Analytical model to monitor the oil conditions on the main components of mining dumpers

Mechanic systems are lubricated with oil and their analysis is one of the best practices among industrial routines. It allows for measuring the number of elements and particles in the lubricant. Furthermore, it improves the equipment health monitoring. In mining, the dumpers are a piece of critical equipment that affects production. The continuous monitoring assures systematic reliability. This work can serve as a good reference for engineers who intend to understand oil data and promote the development of lifetime models of components. This paper studies the lifetime expectation of the main components of T6, T16, TH315, and JOY dumpers considering oil data. These lifetimes were analyzed by using both, the Cox proportional hazard model and a new robust version of the same model that is the main contribution of this work. The results show that robust version introduced has better performance than Cox classical model. The correlation analysis from oil variables, and operational context information are also included. It allowed us to identify the components and dumpers with a major risk of failure and their relationship with the work site.

Entinostat-Bortezomib Hybrids against Multiple Myeloma.

Although proteasome inhibitors have emerged as the therapeutic backbone of multiple myeloma treatment, patients often relapse and become drug refractory. The combination between proteasome and histone deacetylase inhibitors has shown to be more efficient compared to monotherapy by enhancing the anti-myeloma activity and improving the patient's lifetime expectancy. Hybrid molecules, combining two drugs/pharmacophores in a single molecular entity, offer improved effectiveness by modulating more than one target and circumventing differences in the pharmacokinetic and pharmacodynamic profiles, which are the main disadvantages of combination therapy. Therefore, eleven histone deacetylase-proteasome inhibitor hybrids were synthesized, combining pharmacophores of entinostat and bortezomib. Compound 3 displayed the strongest antiproliferative activity with an IC50 value of 9.5 nM in the multiple myeloma cells RPMI 8226, 157.7 nM in the same cell line resistant to bortezomib, and 13.1 nM in a 3D spheroid model containing multiple myeloma and mesenchymal stem cells. Moreover, the compound inhibited 33% of histone deacetylase activity when RPMI 8226 cells were treated for 8 h at 10 µM. It also inhibited the proteasome activity with an IC50 value of 23.6 nM.

Air-cooled condensers optimization for novel Ultra-Low Charge ammonia chillers to achieve competitive packaged units

Novel Ultra-Low Charge (ULC) ammonia chillers are being investigated as a highly efficient and sustainable solution in the field of refrigeration with natural fluids. These chillers were conceived to minimize the refrigerant charge using air-cooled condensers, semi-hermetic compressors, and direct expansion evaporators, becoming reliable solutions for commercial and industrial applications. However, the economic feasibility of ULC packaged units is still questioned, in the long term, compared to traditional ammonia chillers. Accordingly, this paper focuses on the air-cooled condensers optimization due to both, its investment cost relevancy over the packaged unit and its direct influence on the system performance. For this purpose, the experimental performance data of a commercial ULC ammonia chiller of 230 kW have been used to validate a numerical model which predicts the Seasonal Performance Energy Ratio (SEPR) and the Net Present Value (NPV) of the unit. Considering the commercial unit as the baseline case, the number of parallel condensers together with the condensing set point have been optimised to maximise the NPV along the lifetime expectancy of the unit. The results reported an optimal condensing temperature of 12 K above the outdoor temperature for the operating conditions defined in the Eco-Design Directive 2015/1095 and an optimal number of single parallel condensers which ranges from four to six depending on the lifetime considered and the interest rate. Likewise, the NPV varies from 4 000 €, at the fifth year of operation, up to a range between 15 000 € and 35 000 € at the twentieth year of operation.

Prognosis-driven reliability analysis and replacement policy optimization for two-phase continuous degradation

Numerous industrial assets inevitably encounter defect emergence during actual operation, which significantly aggravates the degradation process. This study investigates a prognosis-driven, multi-threshold inspection and replacement model for two-phase continuous degradation. Inspections are equally space to reveal the health state as well as real-time degradation level. Three degrees of control limits, namely corrective limit, defective limit and normal limit are scheduled to manipulate replacement frequencies under separate system states. At an inspection, if the system is diagnosed as normal while the degradation exceeds the normal limit, preventive replacement is postponed according to: (a) residual lifetime expectation adjusted by a control coefficient, and (b) defect identification time, whichever occurs first. Otherwise if the system is found defective with degradation exceeding the defective limit, replacement is also postponed according to a stricter coefficient. The cost model is formulated, which seeks to minimize the long-run cost rate through the joint optimization of inspection interval, control limits and safety coefficients. The applicability of the proposed model is justified via a case study on high-speed rail bearings.

Prevalence of atrial fibrillation – a comprehensive nationwide analysis in Finland

Abstract Introduction Prevalence of atrial fibrillation (AF) is strongly associated with age, and with longer life-time expectancy number of AF patients is worldwide strongly increasing. However, nationwide prevalence of AF is not known when primary care data as well is accessible. Purpose The FinACAF-study is a nationwide registry study including of all AF patients searched from all available national health care registers. To our knowledge, this is the first nationwide AF study including both primary, secondary, and tertiary health care register data. The aim of this study was to assess the prevalence of AF in unselected nationwide population in Finland. Methods In the FinACAF study we gathered data of all AF patients (hospitalizations and outpatient specialist visits and primary health care, and National Reimbursement Register) from all national health care registers from 01st January 2004 to 31st December 2018. The annual prevalence on December 31st of each year 2007–2018 was calculated as the cumulative number of patients alive with AF divided by the number of Finnish population on the last day of that year. The prevalence is presented for population ≥20 years, and with the entire population as the background population, as well as for populations ≥65 years, and ≥75 years. Results In total, 411,387 patients with the diagnosis of AF were documented during 2004–2018 in Finland. The number of adult patients with AF at the end of the study period in 2018 was 226,847, corresponding to an AF prevalence of 5.2% in the age group ≥20 years. The prevalence in the total Finnish population was 4.1%. The prevalence rates increased remarkably with increasing age and were higher in men compared to women (5.9% vs. 4.6%, p&amp;lt;0.001) in all age groups (Figure 1). The prevalence of AF in the adult population increased remarkably from 2.5% in 2007 to 5.2% in 2018 (p&amp;lt;0.001) (Figure 2). Among the population ≥65 years the prevalence in 2018 was 15.3%, and in the elderly, ≥75 years the prevalence of AF was 23.4%. Conclusions Based on comprehensive, nationwide data – also including the primary care – we observed extremely increasing prevalence of AF in the older population, as well as remarkably increasing prevalence of AF over time. Funding Acknowledgement Type of funding sources: Public hospital(s). Main funding source(s): Helsinki and Uusimaa Hospital District

Reduction of Life Time Expectation of Standard Duplex Stainless Steel Exposed to Hydrogen under Corrosion Fatigue Conditions

In geothermal environment corrosion fatigue lowers the lifetime expectancy of high alloyed steels. Therefore, cathodic protection enhances corrosion resistance although hydrogen is produced during the cathodic reactions under applied potential. Corrosion fatigue of standard duplex stainless steel X2CrNiMoN22-5-3, 1.4462 specimen loaded with hydrogen was investigated in a specifically designed corrosion chamber surrounded by the Northern German Basin electrolyte at 369 K. The reactions of the microstructure associated with hydrogen incorporation lowers the number of cycles to failure of specimen significantly at various stress amplitudes, for example at σa = 275 MPa and USHE = -36 mV by 80%. Hydrogen enhances crack propagation and early failure due to the degradation of the mechanical properties of the ferritic phase.

An Electrolytic Capacitor-Less PV Micro-Inverter Based on CLL Resonant Conversion With a Power Control Scheme Using Resonant Circuit Voltage Control Loops

A power control scheme with maximum power point tracking based on solely voltage feedback control loops is proposed in this paper for a dc/ac isolated high frequency PV micro-inverter. The presented power circuit topology consists of an integrated continuous conduction mode (CCM) boost converter with an asymmetrical pulse-witch modulation (APWM) controlled CLL step-up resonant converter and a half-bridge grid-side inverter. The presented topology is capable of achieving CCM input current and a wide range of zero voltage switching (ZVS) operation for the front-end stage. The proposed power control scheme, as well as the developed maximum power point tracking (MPPT) control technique utilize the resonant circuit’s resonant capacitor voltage and the APWM input voltage of the resonant circuit only to achieve MPPT and to control the active power of the overall system. By doing so, a large electrolytic input filtering capacitor is not needed. This allows small size film capacitors to be used and improves the system lifetime expectancy. The theoretical analysis and the detailed descriptions of the proposed power control scheme for the presented PV micro-inverter are provided. Simulation and hardware results on a 220 W with 120 Vac, 60 Hz output hardware prototype are presented to demonstrate the performance of the proposed PV inverter system.