Measurement and analysis of ‘small’ packages in next‐day air shipments

Packaged goods are shipped globally using various means of transportation. Over the past two decades, there has been a continuous increase in studies that measure and analyse dynamic events that occur to packages during transportation and handling. These data offer useful information to design and test packages, and provide protection from potential hazards like drops and impacts. However, none of the past studies are directed towards single packages regarded as ‘smalls’. ‘Smalls’ or small‐package product systems are defined as those with volume of less than 0.013 m³, a longest dimension of 0.356 m and a weight of 4.54 kg or less. Packages that qualify for these specifications are often mixed together in a large carrying bag and handled with other single parcel shipments. This study measured and analysed the effect of moving this category of single packages through expedited shipments in the USA. The results showed that these packages experienced as many as 27 events comprising of drops or tosses in a one‐way shipment, and a maximum of 5.01 m of near‐zero G travel distance representing long ‘tosses’. Copyright © 2009 John Wiley & Sons, Ltd.     

Measurement and analysis of the next‐day air shipping environment for mid‐sized and lightweight packages for DHL,FedEx and United Parcel Service

The past decade has shown a great increase in the number of direct to consumer shipments of products and packages. As a result, parcel delivery companies like DHL, FedEx, UPS and the USPS have strengthened their presence in air transport. Using cargo planes, they route packages from various destinations to large airport hubs, where they sort millions of packages and ship them to their destinations the next morning. There is a continuous need to quantify what happens to these packages as they are handled both manually during collection and delivery and on large high‐speed conveying and sortation equipment at hubs. This study measured and compared shock and drop events for these carriers during next‐day and 2‐day shipping service. Copyright © 2006 John Wiley & Sons, Ltd.     

Measurement and analysis of international air parcel shipping environment for DHL and FedEx between Europe and United States

Various studies have been conducted to determine the dynamics that single packages undergo during distribution between destinations as a function of package size and weight and carrier. Previous studies have normally focused on regional and domestic measurements of these environments in Europe and North America. However, no information is available to determine the international handling and shipping environment of single parcels between the two continents. This study used instrumented packages containing triaxial accelerometers. The measured shocks were analysed to determine the velocity change levels as a function of the events measured in the distribution environment and to develop data for drop heights that can be used for package testing. This study provides a comparison of DHL and FedEx, the two largest international parcel carriers. Copyright © 2007 John Wiley & Sons, Ltd.     

Measurement and analysis of shocks to products packaged in pails in single parcel ground shipments

The objective of this study was to measure and analyse the shocks and impacts experienced by pails in the single parcel distribution environment, with and without a secondary corrugated shipper. The study was conducted in the FedEx Ground shipping environment in the USA. Instrumented 5 gal pails were shipped with and without an outer corrugated box, and with and without handling (precautionary warning) labels, from East Lansing, Michigan to destinations in California and New York. Data recorders were used to collect and analyse shock distribution data (drop heights, drop orientations and number of drops). The results showed that the precautionary labels had no effect in improving the handling or reducing the drop height levels for both corrugated boxes and pails in this environment. Pails without boxes experienced 10 drops per one‐way trip with an average drop height of 0.23 m (9 in). Pails with boxes experienced 18 drops per one‐way trip with a higher average drop height of 0.30 m (12 in), which amounted to 80% more drops at a 25% higher drop height level than pails without boxes. Impact orientations of pails without boxes showed that 60% of the drops occurred on the sides, and 40% on the bottom. Pails shipped in corrugated boxes showed 22% of the drops occurred on the bottoms, 34% on the side faces, 28% on edges and remaining 16% on the corners. The data collected was analysed to develop pre‐shipment package performance tests that can be conducted in a lab environment. Copyright © 2009 John Wiley & Sons, Ltd.     

Measurement and analysis of delivery van vibration levels to simulate package testing for parcel delivery in Hungary

In the past several decades, there continues to be an increase in both domestic and international online and catalogue shipments that requires an increase in shipments and handling of parcels by single parcel delivery companies. This study measured the vibration levels that occur in parcel delivery shipments from pickup to delivery, especially the sections involving delivery vans and small vehicles over ground road transportation in Hungary. Goods that were shipped in the regions studied almost always travel at least once by van on varying road conditions such as motorways, main, side or city roads to deliver parcels to the final destination. The aim of this paper was to provide an understanding of vibration levels that occur during van transportation that can be used to pre‐shipment test new packages to prevent damage. The measured acceleration‐time data were analyzed in terms of power spectral densities (PSDs) and presented with statistical data to provide an understanding of the variability of intensity. The separated and averaged vibration levels that were measured in this study were compared with the American Society of Testing and Materials and the International Safe Transit Association vibration profiles for pickup and delivery vehicle in the form of PSD spectrums. Based on the analyzed data of this study, PSD spectra were provided for various route conditions as well as composite spectra, which can be used to simulate the measured vibration conditions representing van shipments.     

A study of the effect of pictorial markings and warning labels on handling of packages in the DHL single‐parcel environment

Over the past two decades, there has been a heavy influx in the number of direct‐to‐consumer express shipments of packaged products. As a consequence, parcel delivery companies, such as DHL, FedEx and UPS, have strengthened their presence in air transport. This study measured and analysed the effect of moving single packages through air shipments in the USA using one of the newest service providers, DHL. The study also quantified the effect of placing pictorial markings and warning labels on mid‐sized and lightweight packages when using Next‐Day and 2nd Day services provided by the carrier DHL. Instrumented packages measuring 0.38 m × 0.34 m × 0.34 m and weighing 6.8 kg were shipped from Michigan to California and New York. A total of 48 trips were conducted to collect the data for this study. The results show that for the Next‐Day and 2nd Day service, packages with labels, as compared with those without labels, were subjected to approximately the same number of drops for shipment to California, and approximately 35% less drops for shipments to New York. The drop‐height data for the shipments are presented in terms of drop heights associated with the 90, 95 and 99th percentile of occurrence. Impact orientation is also discussed. Copyright © 2007 John Wiley & Sons, Ltd.     

Measurement and analysis of truck and rail shipping environment in India

Free trade agreements have been on the rise in all regions of the world in the past decade. This has allowed for global distribution and marketing of products in an international market. Products once produced for domestic markets must now be able to compete in international markets without trade barriers. Increased international commerce and manufacturing have forced many packaging and logistics engineers to broaden their true understanding of the global distribution environment. India is a recent entrant on the global arena for manufacturing and services. While China's economic developments have dominated global headlines, India's own growth has been impressive as well, with a gross domestic product rising 5% per annum on average since 1990. India is hence primed to follow China as the next low‐cost manufacturing super power. With an increasing interest from multinational corporations in conducting commerce with India, there arises a great need to understand the conditions of the transportation infrastructure there to promote logistical understanding of the distribution environments. This paper provides a brief overview of the road and rail transportation environment in India. It also provides the results of a 2 year study that measured and analysed truck and rail transport vibration for the major freight distribution routes between New Delhi, Bangalore, Mumbai, Chennai, Hyderabad and Kolkatta. Copyright © 2007 John Wiley & Sons, Ltd.     

Modelling and Thermal Analysis of Tray‐layered Fruits inside Ventilated Packages during Forced‐air Precooling

Ventilated packaging is widely used in the forced‐air precooling practice for horticultural produce. Fresh fruits are living organisms which are sensitive to temperature in turn related to airflow and heat transfer inside package. In this study, a transient mathematical model considering heat of respiration and evaporation is developed to predict the thermal response of tray‐layered fruits in ventilated packages during forced‐air precooling. Specifically, the heat source is combined with the energy conservation equation and loaded into numerical solution by User Defined Function (UDF). Temperature profiles of three variously distributed circular and oblong vents in three different patterns (spaced, paralleled and crossed stacking) are simulated, separately. The results show that the heat source affects fruit cooling process, and the layered fruit in paralleled stacking pattern tends to be cooled better than others. Furthermore, the results indicate that vertical oblong vent could improve the longitudinal and lateral airflow, while non‐central vent design could greatly improve the overall cooling performance. Definitely a triangular distribution of three circular vents was superior to laterally distributed centre vents with 66.5% higher uniformity and 2.5°C lower of the highest temperature. Compared with the three identical vertical oblong vent conditions, vent design with one hand hole and two side vertical oblong vents can be cooled more uniformly with an increase of 6.5%. It is revealed that vents with large major‐to‐minor axis ratio could be applied to balance airflow and ease cooling differences for a rapid but uniform cooling. Experimental validations were performed for Sim2, Sim4 and Sim6, Sim8, Sim9, and good agreement was obtained considering the five vent conditions with the error less than 3.5°C but coordinated later (within the limits of the experimental uncertainty).Thus the numerical model can be used to predict and optimize temperature distribution within precooling packages. Copyright © 2016 John Wiley & Sons, Ltd.     

Limit analysis of plates using the EFG method and second‐order cone programming

The meshless element‐free Galerkin (EFG) method is extended to allow computation of the limit load of plates. A kinematic formulation that involves approximating the displacement field using the moving least‐squares technique is developed. Only one displacement variable is required for each EFG node, ensuring that the total number of variables in the resulting optimization problem is kept to a minimum, with far fewer variables being required compared with finite element formulations using compatible elements. A stabilized conforming nodal integration scheme is extended to plastic plate bending problems. The evaluation of integrals at nodal points using curvature smoothing stabilization both keeps the size of the optimization problem small and also results in stable and accurate solutions. Difficulties imposing essential boundary conditions are overcome by enforcing displacements at the nodes directly. The formulation can be expressed as the problem of minimizing a sum of Euclidean norms subject to a set of equality constraints. This non‐smooth minimization problem can be transformed into a form suitable for solution using second‐order cone programming. The procedure is applied to several benchmark beam and plate problems and is found in practice to generate good upper‐bound solutions for benchmark problems. Copyright © 2009 John Wiley & Sons, Ltd.     

Dispersion analysis and element‐free Galerkin solutions of second‐ and fourth‐order gradient‐enhanced damage models

Gradient‐dependent damage formulations incorporate higher‐order derivatives of state variables in the constitutive equations. Different formulations have been derived for this gradient enhancement, comparison of which is difficult in a finite element context due to higher‐order continuity requirements for certain formulations. On the other hand, the higher‐order continuity requirements are met naturally by element‐free Galerkin (EFG) shape functions. Thus, the EFG method provides a suitable tool for the assessment of gradient enhanced continuum models. Dispersion analyses have been carried out to compare different gradient enhanced models with the non‐local damage model. The formulation of the additional boundary conditions is addressed. Numerical examples show the objectivity with respect to the discretization and the differences between various gradient formulations with second‐ and fourth‐order derivatives. It is shown that with the same underlying internal length scale, very different results can be obtained. Copyright © 2000 John Wiley & Sons, Ltd.     

Large‐deformation and friction analysis of non‐linear elastic cable networks by second‐order cone programming

A new formulation is presented for equilibrium shape analysis of cable networks considering geometrical and material non‐linearities. Friction between cables and joint devices is also considered. The second‐order cone programming (SOCP) problem which has the same solution as that of minimization of total potential energy is solved to obtain the equilibrium configuration. The optimality conditions are derived to verify that the solution satisfies equilibrium conditions and friction laws. Since no assumption on stress state is needed in the proposed method, no process of trial and error is involved. No effort is required to develop any analysis software because SOCP can be solved by using the well‐developed software based on the interior‐point method. Copyright © 2002 John Wiley & Sons, Ltd.     

Measurement and Analysis of Vehicle Vibration for Delivering Packages in Small‐Sized and Medium‐Sized Trucks and Automobiles

In distribution, packaged products are subjected to the variation in vibration levels from transport vehicles that vary in frequency and acceleration while moving to their destinations. This vibration may negatively affect the product or packaging. This study measured and analysed vibration levels in vehicles commonly used to transport packages in the last leg of the package delivery service that is used by single‐parcel carriers. Using data recorders, we monitored vertical, lateral and longitudinal vibrations over 75 h of travel time in five different types of small and medium package delivery vehicles. The study presents these data as power density (PD) spectra and compares it with previously measured PD vibration levels in commercial long‐haul interstate tractor‐trailer truck shipments. Data were collected in the USA and Thailand. Copyright © 2011 John Wiley & Sons, Ltd.     

A family of second‐order boundary dampers for finite element analysis of two and three‐dimensional problems in transient exterior acoustics

Numerical modelling of exterior acoustics problems involving infinite medium requires truncation of the medium at a finite distance from the obstacle or the structure and use of non‐reflecting boundary condition at this truncation surface to simulate the asymptotic behaviour of radiated waves at far field. In the context of the finite element method, Bayliss–Gunzburger–Turkel (BGT) boundary conditions are well suited since they are local in both space and time. These conditions involve ‘damper’ operators of various orders, which work on acoustic pressure p and they have been used in time harmonic problems widely and in transient problems in a limited way. Alternative forms of second‐order BGT operators, which work on ṗ (time derivative of p) had been suggested in an earlier paper for 3D problems but they were neither implemented nor validated. This paper presents detailed formulations of these second‐order dampers both for 2D and 3D problems, implements them in a finite element code and validates them using appropriate example problems. The developed code is capable of handling exterior acoustics problems involving both Dirichlet and Neumann boundary conditions. Copyright © 2000 John Wiley & Sons, Ltd.     

Effect of light‐barrier property of packaging film on the photo‐oxidation and shelf life of cookies based on accelerated tests

The influences of intensity of ultraviolet (UV) light, light‐barrier property of packaging film on the fat photo‐oxidation and accelerated shelf life of cookies were studied. Unpacked cookies were stored at a temperature of 408C and a relative humidity (RH) of 50% for 10 to 65 days, with an intensity of the UV light of 0.3, 1.9 and 9.5 mW/cm². Meanwhile, the same batch of cookies was packed with oriented nylon/polyethylene, polyethylene terephthalate/oriented nylon/polyethylene and bi‐oriented polypropylene/vacuuming aluminized casting polypropylene and stored at the same temperature and RH and UV‐light intensity of 1.9 mW/cm² for more than 40 days. The peroxide values (POV) of cookies were measured under the storage conditions. The results showed that the intensity of the UV light and light‐barrier property of film had notable influence on the photo‐oxidation rate and accelerated shelf life of cookies. According to the threshold of POV, unpacked cookies were rancid less than 32 and 11 days when exposed in light of 1.9 and 9.5 mW/cm² in the accelerated test, respectively. In contrast, the shelf life of unpacked cookies in darkness, or cookies packed in high light‐barrier package was more than 75 days. Logarithm of POV and store‐time relationship under different UV‐light illumination was successfully fitted by linear regression under the same temperature, RH and the accelerated shelf‐life‐based oxide index was estimated. Copyright © 2008 John Wiley & Sons, Ltd.     

Cytokine Secreting Microparticles Engineer the Fate and the Effector Functions of T‐Cells

T‐cell immunotherapy is a promising approach for cancer, infection, and autoimmune diseases. However, significant challenges hamper its therapeutic potential, including insufficient activation, delivery, and clonal expansion of T‐cells into the tumor environment. To facilitate T‐cell activation and differentiation in vitro, core–shell microparticles are developed for sustained delivery of cytokines. These particles are enriched by heparin to enable a steady release of interleukin‐2 (IL‐2), the major T‐cell growth factor, over 10+ d. The controlled delivery of cytokines is used to steer lineage specification of cultured T‐cells. This approach enables differentiation of T‐cells into central memory and effector memory subsets. It is shown that the sustained release of stromal cell‐derived factor 1α could accelerate T‐cell migration. It is demonstrated that CD4+ T‐cells could be induced to high concentrations of regulatory T‐cells through controlled release of IL‐2 and transforming growth factor beta. It is found that CD8+ T‐cells that received IL‐2 from microparticles are more likely to gain effector functions as compared with traditional administration of IL‐2. Culture of T‐cells within 3D scaffolds that contain IL‐2‐secreting microparticles enhances proliferation as compared with traditional, 2D approaches. This yield a new method to control the fate of T‐cells and ultimately to new strategies for immune therapy.     

An Investigation of PS‐b‐PEO Polymersomes for the Oral Treatment and Diagnosis of Hyperammonemia

Ammonia‐scavenging transmembrane pH‐gradient poly(styrene)‐b‐poly(ethylene oxide) polymersomes are investigated for the oral treatment and diagnosis of hyperammonemia, a condition associated with serious neurologic complications in patients with liver disease as well as in infants with urea cycle disorders. While these polymersomes are highly stable in simulated intestinal fluids at extreme bile salt and osmolality conditions, they unexpectedly do not reduce plasmatic ammonia levels in cirrhotic rats after oral dosing. Incubation in dietary fiber hydrogels mimicking the colonic environment suggests that the vesicles are probably destabilized during the dehydration of the intestinal chyme. The findings question the relevance of commonly used simulated intestinal fluids for studying vesicular stability. With the encapsulation of a pH‐sensitive dye in the polymersome core, the local pH increase upon ammonia influx could be exploited to assess the ammonia concentration in the plasma of healthy and cirrhotic rats as well as in other fluids. Due to its high sensitivity and selectivity, this polymersome‐based assay could prove useful in the monitoring of hyperammonemic patients and in other applications such as drug screening tests.     

Friction and wear properties of polyphenyl ester and graphite filler in the carbon fibre‐reinforced ultra‐high‐molecular‐weight polyethylene composites

Ultra‐high‐molecular‐weight polyethylene (UHMWPE) reinforced with carbon fibre (CF) underwent an enhancement of heat and wear resistant with the addition of polyphenyl ester (POB) and graphite, respectively. The effect of graphite content on the tribological properties of the composites was studied. The wear surface was examined using scanning electron microscope (SEM). The results of the sliding wear tests showed that with graphite loading, wear resistance increased and the coefficient of friction was much more stable. In addition, graphite improved the tribological properties of the composite. Hardness, impact strengths and thermal stability of the composites were enhanced. With increased load, the wear rate of the ultra‐high‐molecular‐weight polyethylene+carbon fibre+polyphenyl ester+10 % graphite composite tended to increase, whereas the coefficient of friction decreased. The adherence and plastic deformation were dominant wear mechanisms for the ultra‐high‐molecular‐weight polyethylene+carbon fibre+polyphenyl ester+graphite composites. The formation of a thin and uniform transfer film was observed.     

A novel method for integrating first‐ and second‐order differential equations in elastohydrodynamic lubrication for the solution of smooth isothermal,line contact problems

This paper contains details of recent developments in the analysis of elastohydrodynamic lubrication problems using the finite element method. A steady state isothermal finite element formulation of the smooth line contact problem with Newtonian lubricant behaviour is presented containing both first‐ and second‐order formulations of the hydrodynamic equation. Previous problems with the limited range of applicability of both first‐ and second‐order finite difference solutions have been overcome by summing both the first‐ and second‐order equations' weighted contributions. Application of the method to a range of problems unattainable by either single first‐ or second‐order formulations is presented. Copyright © 1999 John Wiley & Sons, Ltd.