202 research outputs found

    Parcel lockers vs. home delivery: a model to compare last-mile delivery cost in urban and rural areas

    Get PDF
    Purpose This paper investigates the economic performances of two business-to-consumer (B2C) e-commerce last-mile delivery options -parcel lockers (PLs) and traditional home delivery (HD) in contexts where e-commerce is still at its early stages. It analyses and compares two different implementation contexts, urban and rural areas. Design/methodology/approach This study develops an analytical model that estimates delivery costs for both the PL and HD options. The model is applied to two base cases (representative of urban and rural areas in Italy), and sensitivity analyses are subsequently performed on a set of key variables/parameters (i.e. PL density, PL fill rate and PL annual costs). To support the model development and application, interviews with practitioners (Edwards et al., 2011) were performed. Findings PLs imply lower delivery cost than HD, independently from the implementation area (urban or rural): advantages mainly derive from the higher delivery density and the drastic reduction of failed deliveries. Benefits entailed by PLs are more significant in rural areas due to lower PL investments and annual costs, as well as higher HD costs. Originality/value This paper offers insights to both academics and practitioners. On the academic side, it develops a model to compare the delivery cost of PL and HD, which includes the analysis of urban and rural contexts. This could serve as a platform for developing/informing future analytical/optimisation contributions. On the managerial side, it may support practitioners in making decisions about the implementation of PLs and HD, to benchmark their costs and to identify the main variables and parameters at play

    Enhancing in-store picking for e-grocery: an empirical-based model

    Get PDF
    Purpose: This paper identifies, configures and analyses a solution aimed at increasing the efficiency of in-store picking for e-grocers and combining the traditional store-based option with a warehouse-based logic (creating a back area dedicated to the most required online items). Design/methodology/approach: The adopted methodology is a multi-method approach combining analytical modelling and interviews with practitioners. Interviews were performed with managers, whose collaboration allowed the development and application of an empirically-grounded model, aimed to estimate the performances of the proposed picking solution in its different configurations. Various scenarios are modelled and different policies are evaluated. Findings: The proposed solution entails time benefits compared to traditional store-based picking for three main reasons: lower travel time (due to the absence of offline customers), lower retrieval time (tied to the more efficient product allocation in the back) and lower time to manage stock-outs (since there are no missing items in the back). Considering the batching policies, order picking is always outperformed by batch and zone picking, as they allow for the reduction of the average travelled distance per order. Conversely, zone picking is more efficient than batch picking when demand volumes are high. Originality/value: From an academic perspective, this work proposes a picking solution that combines the store-based and warehouse-based logics (traditionally seen as opposite/alternative choices). From a managerial perspective, it may support the definition of the picking process for traditional grocers that are offering – or aim to offer – e-commerce services to their customers

    Combining crowdsourcing and mapping customer behaviour in last-mile deliveries

    Get PDF
    In the light of the dramatic rise of online sales, last-mile deliveries (i.e., the delivery of products ordered online to the final customer) have been increasingly gaining the attention of both managers and academics. As a matter of fact, they are very critical in terms of effectiveness (as customers demand fast and accurate deliveries), and efficiency (since they imply very high costs). Henceforth, logistics players operating in the B2C e-commerce environment are striving to find and implement innovative solutions, different from the costly traditional by-van home deliveries. Among the options analysed by scholars so far, two promising ones are crowdsourcing logistics (i.e., outsourcing delivery activities to “common” people) and mapping the behaviour of customers (i.e., analysing the probability distribution of the customer presence at home and accordingly scheduling deliveries to minimise the probability of failed deliveries). In this paper, we introduce and study a combination between the two solutions, proposing a variant of the Vehicle Routing Problem, which considers both the Availability Profiles and Occasional Drivers (VRPAPOD). We model the delivery problem as a mixed-integer program and solve it with a branch-and-price algorithm. To analyse the benefit of the combined use of crowdshipping and customers availability profiles (APs), we conduct several experiments in a real context in the city of Milan, randomly extracting 100 customers in a 16 km2 area. The combined solution is compared with two benchmarking models, namely the traditional home delivery (traditional VRP) and the crowdsourcing logistics option (Vehicle Routing Problem with Occasional Drivers (VRPOD)). Results prove that logistics players can achieve important benefits by relying on the crowd and scheduling deliveries according to clients' APs, which become more significant in case of high drivers availability

    Stabilization of urinary biogenic amines measured in clinical chemistry laboratories.

    Get PDF
    Urinary 5-hydroxyindoleacetic acid (5-HIAA), vanillylmandelic (VMA), homovanillic acid (HVA), catecholamines and metanephrines are produced in excess by catecholamine-producing tumors. These biogenic amines are unstable at low or high pH and require hydrochloric acid (HCl) to prevent their degradation. However, HCl addition may result in very low pH causing degradation or deconjugation of several metabolites. This study evaluated the buffering properties of sodium citrate to stabilize all biogenic amines. The metabolite concentrations were measured by LC-MS/MS or by a coulometric assay in 22 urine samples collected native and with HCl or sodium citrate. We studied the effect of pH, time (48 h, four weeks) and storage temperature at 22 °C, 4 °C, and -20 °C. We found that catecholamines degradation was prevented by HCl and citrate and that 5-HIAA was degraded in 5 out of 22 samples collected with HCl. All biogenic amines were efficiently stabilized by citrate for four weeks at 22 °C, except epinephrine (48 h at 4 °C, or four weeks at -20 °C). Sodium citrate did not cause quantification or analytical artefacts concerns. In conclusion, sodium citrate is a non-hazardous alternative to HCl for patients to send unfrozen urine samples to the laboratory which may safely store the sample for four weeks

    Dark, cloud and ghost kitchens: a logistics perspective

    Get PDF
    In recent years multiple countries have witnessed the dramatic diffusion of the so-called “on-demand food delivery”, i.e., a model based on online platforms offering the delivery of freshly prepared meals from restaurants to the customers’ home. In these ecosystems, novel solutions referred to as “Kitchens for Delivery” are being created, which are aimed to fulfil these orders. Differently from traditional restaurants, these are kitchens dedicated to the preparation of online orders only, with no offline customers. This being the context, the present research has a twofold goal. First, identifying and describing the major different models existing in the field (i.e., Dark, Cloud and Ghost Kitchens). Second, estimating their performances from a logistics perspective, by means of an evaluation of their impact on the on-demand food delivery logistics problem. The implemented approach is multi-method, as it combines: (i) the analysis of (black, grey and white) literature, to understand the state of art and map the main solutions; (ii) a simulation study, to assess the changes implied by introducing Ghost Kitchens into the network in terms of delivery performances; (iii) interviews with practitioners, to validate and interpret the results. The research is expected to have both academic and managerial implications. Considering academia, it sheds light on a field that is under-investigated in literature, proposing a classification of extant models, as well as a model to estimate their logistics implications. Considering industry, it provides an estimation of the impact that implementing Ghost Kitchens could have on the most significant logistics performances

    Delivering parcels through a metro-based underground network: an economic analysis

    Get PDF
    This work proposes the introduction of an innovative method to deliver parcels within urban areas through a two- echelon logistic network, exploiting underground public transportation and cargo bikes. A model simulating the delivery of parcels through underground public transportation and cargo bikes is developed and applied to the city of Milan. Different scenarios, characterized by a different number of train stations activated and a number of daily orders, are investigated. Exploiting available capacity at subway trains reduces the impact of routing empty vehicles for the public infrastructure provider. Besides, as small, capacitated vehicles, cargo cycles allow having an average higher saturation, with the possibility of running multiple trips within the same day, lowering the impact of non-value adding returns for long-haul vehicles coming from outlying distribution centers. Alongside this, the usage of light vehicles and underground infrastructures help to significantly reduce transportation impacts. Overall, the solution proposed has the potential to radically innovate and improve urban last mile delivery under both economic and environmental perspectives. The present work proposes an innovative solution to deliver parcels, showing that it is sustainable from the logistics service operators' perspective

    Truck-based drone delivery system: An economic and environmental assessment

    Get PDF
    Innovative solutions for last-mile delivery have sparked great interest among consumers and logistics operators. The combination of new technologies with existing ones can lead to new possible last-mile delivery configurations, among which truck-drone joint delivery is one of the most promising. This paper evaluates the environmental and economic sustainability of a last-mile delivery solution involving electric trucks equipped with drones, and it provides a comparison with traditional logistics systems. The comparative life cycle assessment methodology is used to quantify the greenhouse gas emissions per parcel delivered. The total cost of ownership methodology is adopted for the economic analysis. Results suggest that the truck-drone alternative leads to significant emissions reductions, while its cost performance is primarily affected by the drone automation level

    Ph-positive CML in blastic phase with monosomy 7 in a Down syndrome patient. Monitoring by interphase cytogenetics and demonstration of maternal allelic loss

    Get PDF
    We report a case of Ph-positive chronic myelocytic leukemia in blastic phase in an 11-year-old boy with Down syndrome. Monosomy 7 was the only additional chromosomal anomaly in the blastic clone. Fluorescence in situ hybridization analysis on interphase nuclei with a centromeric probe specific to chromosome 7 proved to be efficient in disease monitoring; and showed, together with the results of chromosome analysis on metaphases, that B- lymphocytes at the origin of an EBV-established line were not part of the leukemic clone. The study of DNA polymorphisms showed that the origin of the constitutional trisomy 21 was a maternal anaphase I nondisjunction, that the chromosome 7 lost in the blastic marrow clone was the maternal one, and led us to postulate that the mother's chromosomes are prone to impairment of normal disjunction. The study of allelic losses of chromosome 7 loci proved to be a further possibility for disease monitoring

    Constitutional trisomy 8 as first mutation in multistep carcinogenesis: clinical, cytogenetic, and molecular data on three cases.

    Get PDF
    Three patients, with constitutional trisomy 8 mosaicism (CT8M), who developed a malignancy are reported. The diagnoses were refractory anaemia, acute lymphoblastic leukaemia, and idiopathic myelofibrosis. In the child with acute leukaemia, the CT8M was diagnosed at birth due to severe dysmorphisms and malformations; the other two patients showed a milder phenotype, and the CT8M was diagnosed only after the finding of trisomy 8 in neoplastic cells. The review of eight similar, previously reported cases and the clinical, cytogenetic, and molecular studies performed in our patients led us to make the following observations: (1) CT8M predisposes to neoplasms, preferentially to myelo- or lymphoproliferative diseases; (2) a gene dosage effect for glutathione reductase in red blood cells was seen in two of our patients; (3) the wide phenotypic variation of CT8M was confirmed: trisomy 8 in neoplastic cells of phenotypically near-normal cases may be misinterpreted as acquired; and (4) molecular studies suggested a postzygotic origin of the trisomy in our three cases, with the supernumerary chromosome being of paternal origin in one case and of maternal origin in the other two. We postulate that the trisomy 8 in neoplasms may often occur by mitotic nondisjunction in an early embryonic multipotent cell and that what is usually interpreted as an acquired trisomy 8 may in fact be CT8M. The constitutional trisomy 8 would act as a pathogenetically important first mutation in multistep carcinogenesis. Whenever trisomy 8 is found in malignancies, the patient should be reevaluated clinically to exclude CT8M, and CT8M patients should be monitored for the possible development of malignancies

    Motor imagery training speeds up gait recovery and decreases the risk of falls in patients submitted to total knee arthroplasty

    Get PDF
    With Motor imagery (MI), movements are mentally rehearsed without overt actions; this procedure has been adopted in motor rehabilitation, primarily in brain-damaged patients. Here we rather tested the clinical potentials of MI in purely orthopaedic patients who, by definition, should maximally benefit of mental exercises because of their intact brain. To this end we studied the recovery of gait after total knee arthroplasty and evaluated whether MI combined with physiotherapy could speed up the recovery of gait and even limit the occurrence of future falls. We studied 48 patients at the beginning and by the end of the post-surgery residential rehabilitation program: half of them completed a specific MI training supported by computerized visual stimulation (experimental group); the other half performed a non-motoric cognitive training (control group). All patients also had standard physiotherapy. By the end of the rehabilitation, the experimental group showed a better recovery of gait and active knee flexion-extension movements, and less pain. The number of falls or near falls after surgery was significantly lower in the experimental group. These results show that MI can improve gait abilities and limit future falls in orthopaedic patients, without collateral risks and with limited costs
    corecore