Abstract: A method for maintaining center of gravity (COG) of a storage unit is provided. A server receives a first request for placing an item in a storage facility. The server identifies a storage unit in the storage facility and slots available in the storage unit for placing the item. The server selects a first slot from the available slots to place the item, such that when the item is placed in the first slot, the COG of the storage unit is maintained within a COG tolerance region of the storage unit. The server further maintains the COG within the COG tolerance region after one or more items are picked from the storage unit. The server identifies new slots for rearranging items remaining in the storage unit after the items are picked and thus maintains the COG of the storage unit within the COG tolerance region.

Abstract: The invention provides an interface assembly for delivering an ionized analyte from an ionization apparatus into an ion mobility spectrometer. This allows analysis of biological and non-biological samples, even non-volatile solids, via differential mobility spectrometry, without fragmentation of molecules. The invention also provides portable sample analysis systems that operate at ambient pressure. Systems of the invention may be used for high molecular weight species detection, for example, drinking water contaminants, pathogenic biological agents, bio-organic substances, non-biological material, peptides, proteins, oligonucleotides, polymers, bacteria, and hydrocarbons.

Abstract: The invention provides an interface assembly for delivering an ionized analyte from an ionization apparatus into an ion mobility spectrometer. This allows analysis of biological and non-biological samples, even non-volatile solids, via differential mobility spectrometry, without fragmentation of molecules. The invention also provides portable sample analysis systems that operate at ambient pressure. Systems of the invention may be used for high molecular weight species detection, for example, drinking water contaminants, pathogenic biological agents, bio-organic substances, non-biological material, peptides, proteins, oligonucleotides, polymers, bacteria, and hydrocarbons.

Abstract: The invention provides an interface assembly for delivering an ionized analyte from an ionization apparatus into an ion mobility spectrometer. This allows analysis of biological and non-biological samples, even non-volatile solids, via differential mobility spectrometry, without fragmentation of molecules. The invention also provides portable sample analysis systems that operate at ambient pressure. Systems of the invention may be used for high molecular weight species detection, for example, drinking water contaminants, pathogenic biological agents, bio-organic substances, non-biological material, peptides, proteins, oligonucleotides, polymers, bacteria, and hydrocarbons.

Abstract: The invention provides an interface assembly for delivering an ionized analyte from an ionization apparatus into an ion mobility spectrometer. This allows analysis of biological and non-biological samples, even non-volatile solids, via differential mobility spectrometry, without fragmentation of molecules. The invention also provides portable sample analysis systems that operate at ambient pressure. Systems of the invention may be used for high molecular weight species detection, for example, drinking water contaminants, pathogenic biological agents, bio-organic substances, non-biological material, peptides, proteins, oligonucleotides, polymers, bacteria, and hydrocarbons.